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• UML assignment question

  - by waitinforatrain

  Hi guys, Sorry, I know this is a very lame question to ask and not of any use to anyone else. I have an assignment in UML due tomorrow and I don't even know the basics (all-nighter ahead!). I'm not looking for a walkthrough, I simply want your opinion on something. The assignment is as follows (you only need to skim over it!): ============= Gourmet Surprise (GS) is a small catering firm with five employees. During a typical weekend, GS caters fifteen events with twenty to fifty people each. The business has grown rapidly over the past year and the owner wants to install a new computer system for managing the ordering and buying process. GS has a set of ten standard menus. When potential customers call, the receptionist describes the menus to them. If the customer decides to book an event (dinner, lunch, picnic, finger food etc.), the receptionist records the customer information (e.g., name, address, phone number, etc.) and the information about the event (e.g., place, date, time, which one of the standard menus, total price) on a contract. The customer is then faxed a copy of the contract and must sign and return it along with a deposit (often a credit card or by check) before the event is officially booked. The remaining money is collected when the catering is delivered. Sometimes, the customer wants something special (e.g., birthday cake). In this case, the receptionist takes the information and gives it to the owner who determines the cost; the receptionist then calls the customer back with the price information. Sometimes the customer accepts the price, other times, the customer requests some changes that have to go back to the owner for a new cost estimate. Each week, the owner looks through the events scheduled for that weekend and orders the supplies (e.g., plates) and food (e.g., bread, chicken) needed to make them. The owner would like to use the system for marketing as well. It should be able to track how customers learned about GS, and identify repeat customers, so that GS can mail special offers to them. The owner also wants to track the events on which GS sent a contract, but the customer never signed the contract and actually booked a GS. Exercise: Create an activity diagram and a use case model (complete with a set of detail use case descriptions) for the above system. Produce an initial domain model (class diagram) based on these descriptions. Elaborate the use cases into sequence diagrams, and include any state diagrams necessary. Finally use the information from these dynamic models to expand the domain model into a full application model. ============= In your opinion, do you think this question is asking me to come up with a package for an online ordering system to replace the system described above, or to create UML diagrams that facilitate the existing telephone-based system?

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• C# Monte Carlo Incremental Risk Calculation optimisation, random numbers, parallel execution

  - by m3ntat

  My current task is to optimise a Monte Carlo Simulation that calculates Capital Adequacy figures by region for a set of Obligors. It is running about 10 x too slow for where it will need to be in production and number or daily runs required. Additionally the granularity of the result figures will need to be improved down to desk possibly book level at some stage, the code I've been given is basically a prototype which is used by business units in a semi production capacity. The application is currently single threaded so I'll need to make it multi-threaded, may look at System.Threading.ThreadPool or the Microsoft Parallel Extensions library but I'm constrained to .NET 2 on the server at this bank so I may have to consider this guy's port, http://www.codeproject.com/KB/cs/aforge_parallel.aspx. I am trying my best to get them to upgrade to .NET 3.5 SP1 but it's a major exercise in an organisation of this size and might not be possible in my contract time frames. I've profiled the application using the trial of dotTrace (http://www.jetbrains.com/profiler). What other good profilers exist? Free ones? A lot of the execution time is spent generating uniform random numbers and then translating this to a normally distributed random number. They are using a C# Mersenne twister implementation. I am not sure where they got it or if it's the best way to go about this (or best implementation) to generate the uniform random numbers. Then this is translated to a normally distributed version for use in the calculation (I haven't delved into the translation code yet). Also what is the experience using the following? http://quantlib.org http://www.qlnet.org (C# port of quantlib) or http://www.boost.org Any alternatives you know of? I'm a C# developer so would prefer C#, but a wrapper to C++ shouldn't be a problem, should it? Maybe even faster leveraging the C++ implementations. I am thinking some of these libraries will have the fastest method to directly generate normally distributed random numbers, without the translation step. Also they may have some other functions that will be helpful in the subsequent calculations. Also the computer this is on is a quad core Opteron 275, 8 GB memory but Windows Server 2003 Enterprise 32 bit. Should I advise them to upgrade to a 64 bit OS? Any links to articles supporting this decision would really be appreciated. Anyway, any advice and help you may have is really appreciated.

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• How to Solve N-Queens Problem in Scheme?

  - by Philip

  Hi, I'm stuck on the extended exercise 28.2 of How to Design Programs. Here is the link to the question: http://www.htdp.org/2003-09-26/Book/curriculum-Z-H-35.html#node_chap_28 I used a vector of true or false values to represent the board instead of using a list. This is what I've got which doesn't work: #lang Scheme (define-struct posn (i j)) ;takes in a position in i, j form and a board and returns a natural number that represents the position in index form ;example for board xxx ; xxx ; xxx ;(0, 1) - 1 ;(2, 1) - 7 (define (board-ref a-posn a-board) (+ (* (sqrt (vector-length a-board)) (posn-i a-posn)) (posn-j a-posn))) ;reverse of the above function ;1 - (0, 1) ;7 - (2, 1) (define (get-posn n a-board) (local ((define board-length (sqrt (vector-length a-board)))) (make-posn (floor (/ n board-length)) (remainder n board-length)))) ;determines if posn1 threatens posn2 ;true if they are on the same row/column/diagonal (define (threatened? posn1 posn2) (cond ((= (posn-i posn1) (posn-i posn2)) #t) ((= (posn-j posn1) (posn-j posn2)) #t) ((= (abs (- (posn-i posn1) (posn-i posn2))) (abs (- (posn-j posn1) (posn-j posn2)))) #t) (else #f))) ;returns a list of positions that are not threatened or occupied by queens ;basically any position with the value true (define (get-available-posn a-board) (local ((define (get-ava index) (cond ((= index (vector-length a-board)) '()) ((vector-ref a-board index) (cons index (get-ava (add1 index)))) (else (get-ava (add1 index)))))) (get-ava 0))) ;consume a position in the form of a natural number and a board ;returns a board after placing a queen on the position of the board (define (place n a-board) (local ((define (foo x) (cond ((not (board-ref (get-posn x a-board) a-board)) #f) ((threatened? (get-posn x a-board) (get-posn n a-board)) #f) (else #t)))) (build-vector (vector-length a-board) foo))) ;consume a list of positions in the form of natural number and consumes a board ;returns a list of boards after placing queens on each of the positions on the board (define (place/list alop a-board) (cond ((empty? alop) '()) (else (cons (place (first alop) a-board) (place/list (rest alop) a-board))))) ;returns a possible board after placing n queens on a-board ;returns false if impossible (define (placement n a-board) (cond ((zero? n) a-board) (else (local ((define available-posn (get-available-posn a-board))) (cond ((empty? available-posn) #f) (else (or (placement (sub1 n) (place (first available-posn) a-board)) (placement/list (sub1 n) (place/list (rest available-posn) a-board))))))))) ;returns a possible board after placing n queens on a list of boards ;returns false if all the boards are not valid (define (placement/list n boards) (cond ((empty? boards) #f) ((zero? n) (first boards)) ((not (boolean? (placement n (first boards)))) (first boards)) (else (placement/list n (rest boards)))))

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• F# Add Constructor to a Record?

  - by akaphenom

  Basically I want to have a single construct to deal with serializing to both JSON and formatted xml. Records workd nicley for serializing to/from json. However XmlSerializer requires a parameterless construtor. I don't really want to have to go through the exercise of building class objects for these constructs (principal only). I was hoping there could be some shortcut for getting a parameterless constructor onto a record (perhaps with a wioth statement or something). I can't get it to behave - has anybody in the community had any luck? module JSONExample open System open System.IO open System.Net open System.Text open System.Web open System.Xml open System.Security.Authentication open System.Runtime.Serialization //add assemnbly reference System.Runtime.Serialization System.Xml open System.Xml.Serialization open System.Collections.Generic [<DataContract>] type ChemicalElementRecord = { [<XmlAttribute("name")>] [<field: DataMember(Name="name") >] Name:string [<XmlAttribute("name")>] [<field: DataMember(Name="boiling_point") >] BoilingPoint:string [<XmlAttribute("atomic-mass")>] [<field: DataMember(Name="atomic_mass") >] AtomicMass:string } [<XmlRoot("freebase")>] [<DataContract>] type FreebaseResultRecord = { [<XmlAttribute("code")>] [<field: DataMember(Name="code") >] Code:string [<XmlArrayAttribute("results")>] [<XmlArrayItem(typeof<ChemicalElementRecord>, ElementName = "chemical-element")>] [<field: DataMember(Name="result") >] Result: ChemicalElementRecord array [<XmlElement("message")>] [<field: DataMember(Name="message") >] Message:string } let getJsonFromWeb() = let query = "[{'type':'/chemistry/chemical_element','name':null,'boiling_point':null,'atomic_mass':null}]" let query = query.Replace("'","\"") let queryUrl = sprintf "http://api.freebase.com/api/service/mqlread?query=%s" "{\"query\":"+query+"}" let request : HttpWebRequest = downcast WebRequest.Create(queryUrl) request.Method <- "GET" request.ContentType <- "application/x-www-form-urlencoded" let response = request.GetResponse() let result = try use reader = new StreamReader(response.GetResponseStream()) reader.ReadToEnd(); finally response.Close() let data = Encoding.Unicode.GetBytes(result); let stream = new MemoryStream() stream.Write(data, 0, data.Length); stream.Position <- 0L stream let test = // get some JSON from the web let stream = getJsonFromWeb() // convert the stream of JSON into an F# Record let JsonSerializer = Json.DataContractJsonSerializer(typeof<FreebaseResultRecord>) let result: FreebaseResultRecord = downcast JsonSerializer.ReadObject(stream) // save the Records to disk as JSON use fs = new FileStream(@"C:\temp\freebase.json", FileMode.Create) JsonSerializer.WriteObject(fs,result) fs.Close() // save the Records to disk as System Controlled XML let xmlSerializer = DataContractSerializer(typeof<FreebaseResultRecord>); use fs = new FileStream(@"C:\temp\freebase.xml", FileMode.Create) xmlSerializer.WriteObject(fs,result) fs.Close() use fs = new FileStream(@"C:\temp\freebase-pretty.xml", FileMode.Create) let xmlSerializer = XmlSerializer(typeof<FreebaseResultRecord>) xmlSerializer.Serialize(fs,result) fs.Close() ignore(test)

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• Automatically generate table of function pointers in C.

  - by jeremytrimble

  I'm looking for a way to automatically (as part of the compilation/build process) generate a "table" of function pointers in C. Specifically, I want to generate an array of structures something like: typedef struct { void (*p_func)(void); char * funcName; } funcRecord; /* Automatically generate the lines below: */ extern void func1(void); extern void func2(void); /* ... */ funcRecord funcTable[] = { { .p_func = &func1, .funcName = "func1" }, { .p_func = &func2, .funcName = "func2" } /* ... */ }; /* End automatically-generated code. */ ...where func1 and func2 are defined in other source files. So, given a set of source files, each of which which contain a single function that takes no arguments and returns void, how would one automatically (as part of the build process) generate an array like the one above that contains each of the functions from the files? I'd like to be able to add new files and have them automatically inserted into the table when I re-compile. I realize that this probably isn't achievable using the C language or preprocessor alone, so consider any common *nix-style tools fair game (e.g. make, perl, shell scripts (if you have to)). But Why? You're probably wondering why anyone would want to do this. I'm creating a small test framework for a library of common mathematical routines. Under this framework, there will be many small "test cases," each of which has only a few lines of code that will exercise each math function. I'd like each test case to live in its own source file as a short function. All of the test cases will get built into a single executable, and the test case(s) to be run can be specified on the command line when invoking the executable. The main() function will search through the table and, if it finds a match, jump to the test case function. Automating the process of building up the "catalog" of test cases ensures that test cases don't get left out (for instance, because someone forgets to add it to the table) and makes it very simple for maintainers to add new test cases in the future (just create a new source file in the correct directory, for instance). Hopefully someone out there has done something like this before. Thanks, StackOverflow community!

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• Using perl to parse a file and insert specific values into a database

  - by Sean

  Disclaimer: I'm a newbie at scripting in perl, this is partially a learning exercise (but still a project for work). Also, I have a much stronger grasp on shell scripting, so my examples will likely be formatted in that mindset (but I would like to create them in perl). Sorry in advance for my verbosity, I want to make sure I am at least marginally clear in getting my point across I have a text file (a reference guide) that is a Word document converted to text then swapped from Windows to UNIX format in Notepad++. The file is uniform in that each section of the file had the same fields/formatting/tables. What I have planned to do, in a basic way is grab each section, keyed by unique batch job names and place all of the values into a database (or maybe just an excel file) so all the fields can be searched/edited for each job much easier than in the word file and possibly create a web interface later on. So what I want to do is grab each section by doing something like: sed -n '/job_name_1_regex/,/job_name_2_regex/' file.txt --how would this be formatted within a perl script? (grab the section in total, then break it down further from there) To read the file in the script I have open FORMAT_FILE, 'test_format.txt'; and then use foreach $line (<FORMAT_FILE>) to parse the file line by line. --is there a better way? My next problem is that since I converted from a word doc with tables, which looks like: Table Heading 1 Table Heading 2 Heading 1/Value 1 Heading 2/Value 1 Heading 1/Value 2 Heading 2/Value 2 but the text file it looks like: Table Heading 1 Table Heading 2Heading 1/Value 1Heading 1/Value 2Heading 2/Value 1Heading 2/Value 2 So I want to have "Heading 1" and "Heading 2" as a columns name and then put the respective values there. I just am not sure how to get the values in relation to the heading from the text file. The values of Heading 1 will always be the line number of Heading 1 plus 2 (Heading 1, Heading 2, Values for heading 1). I know this can be done in awk/sed pretty easily, just not sure how to address it inside a perl script. After I have all the right values and such, linking it up to a database may be an issue as well, I haven't started looking at the way perl interacts with DBs yet. Sorry if this is a bit scatterbrained...it's still not fully formed in my head.

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• Most efficient method to query a Young Tableau

  - by Matthieu M.

  A Young Tableau is a 2D matrix A of dimensions M*N such that: i,j in [0,M)x[0,N): for each p in (i,M), A[i,j] <= A[p,j] for each q in (j,N), A[i,j] <= A[i,q] That is, it's sorted row-wise and column-wise. Since it may contain less than M*N numbers, the bottom-right values might be represented either as missing or using (in algorithm theory) infinity to denote their absence. Now the (elementary) question: how to check if a given number is contained in the Young Tableau ? Well, it's trivial to produce an algorithm in O(M*N) time of course, but what's interesting is that it is very easy to provide an algorithm in O(M+N) time: Bottom-Left search: Let x be the number we look for, initialize i,j as M-1, 0 (bottom left corner) If x == A[i,j], return true If x < A[i,j], then if i is 0, return false else decrement i and go to 2. Else, if j is N-1, return false else increment j This algorithm does not make more than M+N moves. The correctness is left as an exercise. It is possible though to obtain a better asymptotic runtime. Pivot Search: Let x be the number we look for, initialize i,j as floor(M/2), floor(N/2) If x == A[i,j], return true If x < A[i,j], search (recursively) in A[0:i-1, 0:j-1], A[i:M-1, 0:j-1] and A[0:i-1, j:N-1] Else search (recursively) in A[i+1:M-1, 0:j], A[i+1:M-1, j+1:N-1] and A[0:i, j+1:N-1] This algorithm proceed by discarding one of the 4 quadrants at each iteration and running recursively on the 3 left (divide and conquer), the master theorem yields a complexity of O((N+M)**(log 3 / log 4)) which is better asymptotically. However, this is only a big-O estimation... So, here are the questions: Do you know (or can think of) an algorithm with a better asymptotical runtime ? Like introsort prove, sometimes it's worth switching algorithms depending on the input size or input topology... do you think it would be possible here ? For 2., I am notably thinking that for small size inputs, the bottom-left search should be faster because of its O(1) space requirement / lower constant term.

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• Declare private static members in F#?

  - by acidzombie24

  I decided to port the class in C# below to F# as an exercise. It was difficult. I only notice three problems 1) Greet is visible 2) I can not get v to be a static class variable 3) I do not know how to set the greet member in the constructor. How do i fix these? The code should be similar enough that i do not need to change any C# source. ATM only Test1.v = 21; does not work C# using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CsFsTest { class Program { static void Main(string[] args) { Test1.hi("stu"); new Test1().hi(); Test1.v = 21; var a = new Test1("Stan"); a.hi(); a.a = 9; Console.WriteLine("v = {0} {1} {2}", a.a, a.b, a.NotSTATIC()); } } class Test1 { public int a; public int b { get { return a * 2; } } string greet = "User"; public static int v; public Test1() {} public Test1(string name) { greet = name; } public static void hi(string greet) { Console.WriteLine("Hi {0}", greet); } public void hi() { Console.WriteLine("Hi {0} #{1}", greet, v); } public int NotSTATIC() { return v; } } } F# namespace CsFsTest type Test1 = (* public int a; public int b { get { return a * 2; } } string greet = "User"; public static int v; *) [<DefaultValue>] val mutable a : int member x.b = x.a * 2 member x.greet = "User" (*!! Needs to be private *) [<DefaultValue>] val mutable v : int (*!! Needs to be static *) (* public Test1() {} public Test1(string name) { greet = name; } *) new () = {} new (name) = { } (* public static void hi(string greet) { Console.WriteLine("Hi {0}", greet); } public void hi() { Console.WriteLine("Hi {0} #{1}", greet, v); } public int NotSTATIC() { return v; } *) static member hi(greet) = printfn "hi %s" greet member x.hi() = printfn "hi %s #%i" x.greet x.v member x.NotSTATIC() = x.v

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• Constraint Satisfaction Problem

  - by Carl Smotricz

  I'm struggling my way through Artificial Intelligence: A Modern Approach in order to alleviate my natural stupidity. In trying to solve some of the exercises, I've come up against the "Who Owns the Zebra" problem, Exercise 5.13 in Chapter 5. This has been a topic here on SO but the responses mostly addressed the question "how would you solve this if you had a free choice of problem solving software available?" I accept that Prolog is a very appropriate programming language for this kind of problem, and there are some fine packages available, e.g. in Python as shown by the top-ranked answer and also standalone. Alas, none of this is helping me "tough it out" in a way as outlined by the book. The book appears to suggest building a set of dual or perhaps global constraints, and then implementing some of the algorithms mentioned to find a solution. I'm having a lot of trouble coming up with a set of constraints suitable for modelling the problem. I'm studying this on my own so I don't have access to a professor or TA to get me over the hump - this is where I'm asking for your help. I see little similarity to the examples in the chapter. I was eager to build dual constraints and started out by creating (the logical equivalent of) 25 variables: nationality1, nationality2, nationality3, ... nationality5, pet1, pet2, pet3, ... pet5, drink1 ... drink5 and so on, where the number was indicative of the house's position. This is fine for building the unary constraints, e.g. The Norwegian lives in the first house: nationality1 = { :norway }. But most of the constraints are a combination of two such variables through a common house number, e.g. The Swede has a dog: nationality[n] = { :sweden } AND pet[n] = { :dog } where n can range from 1 to 5, obviously. Or stated another way: nationality1 = { :sweden } AND pet1 = { :dog } XOR nationality2 = { :sweden } AND pet2 = { :dog } XOR nationality3 = { :sweden } AND pet3 = { :dog } XOR nationality4 = { :sweden } AND pet4 = { :dog } XOR nationality5 = { :sweden } AND pet5 = { :dog } ...which has a decidedly different feel to it than the "list of tuples" advocated by the book: ( X1, X2, X3 = { val1, val2, val3 }, { val4, val5, val6 }, ... ) I'm not looking for a solution per se; I'm looking for a start on how to model this problem in a way that's compatible with the book's approach. Any help appreciated.

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• Best Practices / Patterns for Enterprise Protection/Remediation of SSNs (Social Security Numbers)

  - by Erik Neu

  I am interested in hearing about enterprise solutions for SSN handling. (I looked pretty hard for any pre-existing post on SO, including reviewing the terriffic SO automated "Related Questions" list, and did not find anything, so hopefully this is not a repeat.) First, I think it is important to enumerate the reasons systems/databases use SSNs: (note—these are reasons for de facto current state—I understand that many of them are not good reasons) Required for Interaction with External Entities. This is the most valid case—where external entities your system interfaces with require an SSN. This would typically be government, tax and financial. SSN is used to ensure system-wide uniqueness. SSN has become the default foreign key used internally within the enterprise, to perform cross-system joins. SSN is used for user authentication (e.g., log-on) The enterprise solution that seems optimum to me is to create a single SSN repository that is accessed by all applications needing to look up SSN info. This repository substitutes a globally unique, random 9-digit number (ASN) for the true SSN. I see many benefits to this approach. First of all, it is obviously highly backwards-compatible—all your systems "just" have to go through a major, synchronized, one-time data-cleansing exercise, where they replace the real SSN with the alternate ASN. Also, it is centralized, so it minimizes the scope for inspection and compliance. (Obviously, as a negative, it also creates a single point of failure.) This approach would solve issues 2 and 3, without ever requiring lookups to get the real SSN. For issue #1, authorized systems could provide an ASN, and be returned the real SSN. This would of course be done over secure connections, and the requesting systems would never persist the full SSN. Also, if the requesting system only needs the last 4 digits of the SSN, then that is all that would ever be passed. Issue #4 could be handled the same way as issue #1, though obviously the best thing would be to move away from having users supply an SSN for log-on. There are a couple of papers on this: UC Berkely: http://bit.ly/bdZPjQ Oracle Vault: bit.ly/cikbi1

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• Why does the rename() syscall prohibit moving a directory that I can't write to a different director

  - by Daniel Papasian

  I am trying to understand why this design decision was made with the rename() syscall in 4.2BSD. There's nothing I'm trying to solve here, just understand the rationale for the behavior itself. 4.2BSD saw the introduction of the rename() syscall for the purpose of allowing atomic renames/moves of files. From 4.3BSD-Reno/src/sys/ufs/ufs_vnops.c: /* * If ".." must be changed (ie the directory gets a new * parent) then the source directory must not be in the * directory heirarchy above the target, as this would * orphan everything below the source directory. Also * the user must have write permission in the source so * as to be able to change "..". We must repeat the call * to namei, as the parent directory is unlocked by the * call to checkpath(). */ if (oldparent != dp->i_number) newparent = dp->i_number; if (doingdirectory && newparent) { VOP_LOCK(fndp->ni_vp); error = ufs_access(fndp->ni_vp, VWRITE, tndp->ni_cred); VOP_UNLOCK(fndp->ni_vp); So clearly this check was added intentionally. My question is - why? Is this behavior supposed to be intuitive? The effect of this is that one cannot move a directory (located in a directory that one can write) that one cannot write to another directory that one can write to atomically. You can, however, create a new directory, move the links over (assuming one has read access to the directory), and then remove one's write bit on the directory. You just can't do so atomically. % cd /tmp % mkdir stackoverflow-question % cd stackoverflow-question % mkdir directory-1 % mkdir directory-2 % mkdir directory-1/directory-i-cant-write % echo "foo" > directory-1/directory-i-cant-write/contents % chmod 000 directory-1/directory-i-cant-write/contents % chmod 000 directory-1/directory-i-cant-write % mv directory-1/directory-i-cant-write directory-2 mv: rename directory-1/directory-i-cant-write to directory-2/directory-i-cant-write: Permission denied We now have a directory I can't write with contents I can't read that I can't move atomically. I can, however, achieve the same effect non-atomically by changing permissions, making the new directory, using ln to create the new links, and changing permissions. (Left as an exercise to the reader) . and .. are special cased already, so I don't particularly buy that it is intuitive that if I can't write a directory I can't "change .." which is what the source suggests. Is there any reason for this besides it being the perceived correct behavior by the author of the code? Is there anything bad that can happen if we let people atomically move directories (that they can't write) between directories that they can write?

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• Are there programs that iteratively write new programs?

  - by chris

  For about a year I have been thinking about writing a program that writes programs. This would primarily be a playful exercise that might teach me some new concepts. My inspiration came from negentropy and the ability for order to emerge from chaos and new chaos to arise out of order in infinite succession. To be more specific, the program would start by writing a short random string. If the string compiles the programs will log it for later comparison. If the string does not compile the program will try to rewrite it until it does compile. As more strings (mini 'useless' programs) are logged they can be parsed for similarities and used to generate a grammar. This grammar can then be drawn on to write more strings that have a higher probability of compilation than purely random strings. This is obviously more than a little silly, but I thought it would be fun to try and grow a program like this. And as a byproduct I get a bunch of unique programs that I can visualize and call art. I'll probably write this in Ruby due to its simple syntax and dynamic compilation and then I will visualize in processing using ruby-processing. What I would like to know is: Is there a name for this type of programming? What currently exists in this field? Who are the primary contributors? BONUS! - In what ways can I procedurally assign value to output programs beyond compiles(y/n)? I may want to extend the functionality of this program to generate a program based on parameters, but I want the program to define those parameters through running the programs that compile and assigning meaning to the programs output. This question is probably more involved than reasonable for a bonus, but if you can think of a simple way to get something like this done in less than 23 lines or one hyperlink, please toss it into your response. I know that this is not quite meta-programming and from the little I know of AI and generative algorithms they are usually more goal oriented than what I am thinking. What would be optimal is a program that continually rewrites and improves itself so I don't have to ^_^

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• Python. How to iterate through a list of lists looking for a partial match

  - by Becca Millard

  I'm completely stuck on this, without even an idea about how to wrap my head around the logic of this. In the first half of the code, I have successfully generation a list of (thousands of) lists of players names and efficiency scores: eg name_order_list = [["Bob", "Farley", 12.345], ["Jack", "Donalds", 14.567], ["Jack", "Donalds", 13.421], ["Jack", "Donalds", 15.232],["Mike", "Patricks", 10.543]] What I'm trying to do, is come up with a way to make a list of lists of the average efficiency of each player. So in that example, Jack Donalds appears multiple times, so I'd want to recognize his name somehow and average out the efficiency scores. Then sort that new list by efficiency, rather than name. So then the outcome would be like: average_eff_list = [[12.345, "Bob", "Farley"], [14.407, "Jack", "Donalds"], [10.543, "Mike", "Patricks"]] Here's what I tried (it's kind of a mess, but should be readable): total_list = [] odd_lines = [name_order_list[i] for i in range(len(name_order_list)) if i % 2 == 0] even_lines = [name_order_list[i] for i in range(len(name_order_list)) if i % 2 == 1] i = 0 j = i-1 while i <= 10650: iteration = 2 total_eff = 0 while odd_lines[i][0:2] == even_lines[i][0:2]: if odd_lines[i][0:2] == even_lines[j][0:2]: if odd_lines[j][0:2] != even_lines[j][0:2]: total_eff = even_lines[j][2]/(iteration-1) iteration -= 1 #account fr the single (rather than dual) additional entry else: total_eff = total_eff if iteration == 2: total_eff = (odd_lines[i][2] + even_lines[i][2]) / iteration else: total_eff = ((total_eff * (iteration - 2)) + (odd_lines[i][2] + even_lines[i][2])) / iteration iteration += 2 i += 1 j += 1 if i > 10650: break else: if odd_lines[i][0:2] == even_lines[j][0:2]: if odd_lines[j][0:2] != even_lines[j][0:2]: total_eff = (odd_lines[i][2] + even_lines[j][2]) / iteration else: total_eff = ((total_eff * (iteration -2)) + odd_lines[i][2]) / (iteration - 1) if total_eff == 0: #there's no match at all total_odd = [odd_lines[i][2], odd_lines[i][0], odd_lines[i][1]] total_list.append(total_odd) if even_lines[i][0:2] != odd_lines[i+1][0:2]: total_even = [even_lines[i][2], even_lines[i][0], even_lines[i][1]] else: total = [total_eff, odd_lines[i][0], odd_lines[i][1]] total_list.append(total) i += 1 if i > 10650: break else: print(total_list) Now, this runs well enough (doesn't get stuck or print someone's name multiple times) but the efficiency values are off by a large amount, so I know that scores are getting missed somewhere. This is a problem with my logic, I think, so any help would be greatly appreciated. As would any advice about how to loop through that massive list in a smarter way, since I'm sure there is one... EIDT: for this exercise, I need to keep it all in a list format. I can make new lists, but no using dictionaries, classes, etc.

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• Working through exercises in "Cocoa Programming for Mac OS X" - I'm stumped

  - by Zigrivers

  I've been working through the exercises in a book recommended here on stackoverflow, however I've run into a problem and after three days of banging my head on the wall, I think I need some help. I'm working through the "Speakline" exercise where we add a TableView to the interface and the table will display the "voices" that you can choose for the text to speech aspect of the program. I am having two problems that I can't seem to get to the bottom of: I get the following error: * Illegal NSTableView data source (). Must implement numberOfRowsInTableView: and tableView:objectValueForTableColumn:row: The tableView that is supposed to display the voices comes up blank I have a feeling that both of these problems are related. I'm including my interface code here: #import <Cocoa/Cocoa.h> @interface AppController : NSObject <NSSpeechSynthesizerDelegate, NSTableViewDelegate> { IBOutlet NSTextField *textField; NSSpeechSynthesizer *speechSynth; IBOutlet NSButton *stopButton; IBOutlet NSButton *startButton; IBOutlet NSTableView *tableView; NSArray *voiceList; } - (IBAction)sayIt:(id)sender; - (IBAction)stopIt:(id)sender; @end And my implementation code here: #import "AppController.h" @implementation AppController - (id)init { [super init]; //Log to help me understand what is happening NSLog(@"init"); speechSynth = [[NSSpeechSynthesizer alloc] initWithVoice:nil]; [speechSynth setDelegate:self]; voiceList = [[NSSpeechSynthesizer availableVoices] retain]; return self; } - (IBAction)sayIt:(id)sender { NSString *string = [[textField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; //Is the string zero-length? if([string length] == 0) { NSLog(@"String from %@ is a string with a length of %d.", textField, [string length]); [speechSynth startSpeakingString:@"Please enter a phrase first."]; } [speechSynth startSpeakingString:string]; NSLog(@"Started to say: %@", string); [stopButton setEnabled:YES]; [startButton setEnabled:NO]; } - (IBAction)stopIt:(id)sender { NSLog(@"Stopping..."); [speechSynth stopSpeaking]; } - (void) speechSynthesizer:(NSSpeechSynthesizer *)sender didFinishSpeaking:(BOOL)complete { NSLog(@"Complete = %d", complete); [stopButton setEnabled:NO]; [startButton setEnabled:YES]; } - (NSInteger)numberOfRowsInTableView:(NSTableView *)aTableView { return [voiceList count]; } - (id)tableView: (NSTableView *)tv objecValueForTableColumn: (NSTableColumn *)tableColumn row:(NSInteger)row { NSString *v = [voiceList objectAtIndex:row]; NSLog(@"v = %@",v); NSDictionary *dict = [NSSpeechSynthesizer attributesForVoice:v]; return [dict objectForKey:NSVoiceName]; } /* - (BOOL)respondsToSelector:(SEL)aSelector { NSString *methodName = NSStringFromSelector(aSelector); NSLog(@"respondsToSelector: %@", methodName); return [super respondsToSelector:aSelector]; } */ @end Hopefully, you guys can see something obvious that I've missed. Thank you!

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• How and why do I set up a C# build machine?

  - by mmr

  Hi all, I'm working with a small (4 person) development team on a C# project. I've proposed setting up a build machine which will do nightly builds and tests of the project, because I understand that this is a Good Thing. Trouble is, we don't have a whole lot of budget here, so I have to justify the expense to the powers that be. So I want to know: What kind of tools/licenses will I need? Right now, we use Visual Studio and Smart Assembly to build, and Perforce for source control. Will I need something else, or is there an equivalent of a cron job for running automated scripts? What, exactly, will this get me, other than an indication of a broken build? Should I set up test projects in this solution (sln file) that will be run by these scripts, so I can have particular functions tested? We have, at the moment, two such tests, because we haven't had the time (or frankly, the experience) to make good unit tests. What kind of hardware will I need for this? Once a build has been finished and tested, is it a common practice to put that build up on an ftp site or have some other way for internal access? The idea is that this machine makes the build, and we all go to it, but can make debug builds if we have to. How often should we make this kind of build? How is space managed? If we make nightly builds, should we keep around all the old builds, or start to ditch them after about a week or so? Is there anything else I'm not seeing here? I realize that this is a very large topic, and I'm just starting out. I couldn't find a duplicate of this question here, and if there's a book out there I should just get, please let me know. EDIT: I finally got it to work! Hudson is completely fantastic, and FxCop is showing that some features we thought were implemented were actually incomplete. We also had to change the installer type from Old-And-Busted vdproj to New Hotness WiX. Basically, for those who are paying attention, if you can run your build from the command line, then you can put it into hudson. Making the build run from the command line via MSBuild is a useful exercise in itself, because it forces your tools to be current.

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• Python/Biomolecular Physics- Trying to code a simple stochastic simulation of a system exhibiting co

  - by user359597

  *edited 6/17/10 I'm trying to understand how to improve my code (make it more pythonic). Also, I'm interested in writing more intuitive 'conditionals' that would describe scenarios that are commonplace in biochemistry. The conditional criteria in the below program is explained in Answer #2, but I am not satisfied with it- it is correct, but isn't obvious and isn't easy to implement for more complicated conditional scenarios. Ideas welcome. Comments/criticisms welcome. First posting experience @ stackoverflow- please comment on etiquette if needed. The code generates a list of values that are the solution to the following exercise: "In a programming language of your choice, implement Gillespie’s First Reaction Algorithm to study the temporal behaviour of the reaction A---B in which the transition from A to B can only take place if another compound, C, is present, and where C dynamically interconverts with D, as modelled in the Petri-net below. Assume that there are 100 molecules of A, 1 of C, and no B or D present at the start of the reaction. Set kAB to 0.1 s-1 and both kCD and kDC to 1.0 s-1. Simulate the behaviour of the system over 100 s." def sim(): # Set the rate constants for all transitions kAB = 0.1 kCD = 1.0 kDC = 1.0 # Set up the initial state A = 100 B = 0 C = 1 D = 0 # Set the start and end times t = 0.0 tEnd = 100.0 print "Time\t", "Transition\t", "A\t", "B\t", "C\t", "D" # Compute the first interval transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) # Loop until the end time is exceded or no transition can fire any more while t <= tEnd and transition >= 0: print t, '\t', transition, '\t', A, '\t', B, '\t', C, '\t', D t += interval if transition == 0: A -= 1 B += 1 if transition == 1: C -= 1 D += 1 if transition == 2: C += 1 D -= 1 transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) def transitionData(A, B, C, D, kAB, kCD, kDC): """ Returns nTransition, the number of the firing transition (0: A->B, 1: C->D, 2: D->C), and interval, the interval between the time of the previous transition and that of the current one. """ RAB = kAB * A * C RCD = kCD * C RDC = kDC * D dt = [-1.0, -1.0, -1.0] if RAB > 0.0: dt[0] = -math.log(1.0 - random.random())/RAB if RCD > 0.0: dt[1] = -math.log(1.0 - random.random())/RCD if RDC > 0.0: dt[2] = -math.log(1.0 - random.random())/RDC interval = 1e36 transition = -1 for n in range(len(dt)): if dt[n] > 0.0 and dt[n] < interval: interval = dt[n] transition = n return transition, interval if __name__ == '__main__': sim()

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• Backtracking infinite loop

  - by Greenhorn

  This is Exercise 28.1.2 from HtDP. I've successfully implemented the neighbors function and all test cases pass. (define Graph (list (list 'A (list 'B 'E)) (list 'B (list 'E 'F)) (list 'C (list 'D)) (list 'D empty) (list 'E (list 'C 'F)) (list 'F (list 'D 'G)) (list 'G empty))) (define (first-line n alist) (cond [(symbol=? (first alist) n) alist] [else empty])) ;; returns empty if node is not in graph (define (neighbors n g) (cond [(empty? g) empty] [(cons? (first g)) (cond [(symbol=? (first (first g)) n) (first-line n (first g))] [else (neighbors n (rest g))])])) ; test cases (equal? (neighbors 'A Graph) (list 'A (list 'B 'E))) (equal? (neighbors 'B Graph) (list 'B (list 'E 'F))) (equal? (neighbors 'C Graph) (list 'C (list 'D))) (equal? (neighbors 'D Graph) (list 'D empty)) (equal? (neighbors 'E Graph) (list 'E (list 'C 'F))) (equal? (neighbors 'F Graph) (list 'F (list 'D 'G))) (equal? (neighbors 'G Graph) (list 'G empty)) (equal? (neighbors 'H Graph) empty) The problem comes when I copy-paste the code from Figure 77 of the text. It is supposed to determine whether a destination node is reachable from an origin node. However it appears that the code goes into an infinite loop except for the most trivial case where the origin and destination nodes are the same. ;; find-route : node node graph -> (listof node) or false ;; to create a path from origination to destination in G ;; if there is no path, the function produces false (define (find-route origination destination G) (cond [(symbol=? origination destination) (list destination)] [else (local ((define possible-route (find-route/list (neighbors origination G) destination G))) (cond [(boolean? possible-route) false] [else (cons origination possible-route)]))])) ;; find-route/list : (listof node) node graph -> (listof node) or false ;; to create a path from some node on lo-Os to D ;; if there is no path, the function produces false (define (find-route/list lo-Os D G) (cond [(empty? lo-Os) false] [else (local ((define possible-route (find-route (first lo-Os) D G))) (cond [(boolean? possible-route) (find-route/list (rest lo-Os) D G)] [else possible-route]))])) Does the problem lie in my code? Thank you.

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• Stepping into Ruby Meta-Programming: Generating proxy methods for multiple internal methods

  - by mstksg

  Hi all; I've multiply heard Ruby touted for its super spectacular meta-programming capabilities, and I was wondering if anyone could help me get started with this problem. I have a class that works as an "archive" of sorts, with internal methods that process and output data based on an input. However, the items in the archive in the class itself are represented and processed with integers, for performance purposes. The actual items outside of the archive are known by their string representation, which is simply number_representation.to_s(36). Because of this, I have hooked up each internal method with a "proxy method" that converts the input into the integer form that the archive recognizes, runs the internal method, and converts the output (either a single other item, or a collection of them) back into strings. The naming convention is this: internal methods are represented by _method_name; their corresponding proxy method is represented by method_name, with no leading underscore. For example: class Archive ## PROXY METHODS ## ## input: string representation of id's ## output: string representation of id's def do_something_with id result = _do_something_with id.to_i(36) return nil if result == nil return result.to_s(36) end def do_something_with_pair id_1,id_2 result = _do_something_with_pair id_1.to_i(36), id_2.to_i(36) return nil if result == nil return result.to_s(36) end def do_something_with_these ids result = _do_something_with_these ids.map { |n| n.to_i(36) } return nil if result == nil return result.to_s(36) end def get_many_from id result = _get_many_from id return nil if result == nil # no sparse arrays returned return result.map { |n| n.to_s(36) } end ## INTERNAL METHODS ## ## input: integer representation of id's ## output: integer representation of id's def _do_something_with id # does something with one integer-represented id, # returning an id represented as an integer end def do_something_with_pair id_1,id_2 # does something with two integer-represented id's, # returning an id represented as an integer end def _do_something_with_these ids # does something with multiple integer ids, # returning an id represented as an integer end def _get_many_from id # does something with one integer-represented id, # returns a collection of id's represented as integers end end There are a couple of reasons why I can't just convert them if id.class == String at the beginning of the internal methods: These internal methods are somewhat computationally-intensive recursive functions, and I don't want the overhead of checking multiple times at every step There is no way, without adding an extra parameter, to tell whether or not to re-convert at the end I want to think of this as an exercise in understanding ruby meta-programming Does anyone have any ideas? edit The solution I'd like would preferably be able to take an array of method names @@PROXY_METHODS = [:do_something_with, :do_something_with_pair, :do_something_with_these, :get_many_from] iterate through them, and in each iteration, put out the proxy method. I'm not sure what would be done with the arguments, but is there a way to test for arguments of a method? If not, then simple duck typing/analogous concept would do as well.

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• Implementing default constructors

  - by James

  Implement the default constructor, the constructors with one and two int parameters. The one-parameter constructor should initialize the first member of the pair, the second member of the pair is to be 0. Overload binary operator + to add the pairs as follows: (a, b) + (c, d) = (a + c, b + d); Overload the - analogously. Overload the * on pairs ant int as follows: (a, b) * c = (a * c, b * c). Write a program to test all the member functions and overloaded operators in your class definition. You will also need to write accessor (get) functions for each member. The definition of the class Pairs: class Pairs { public: Pairs(); Pairs(int first, int second); Pairs(int first); // other members and friends friend istream& operator>> (istream&, Pair&); friend ostream& operator<< (ostream&, const Pair&); private: int f; int s; }; Self-Test Exercise #17: istream& operator (istream& ins, Pair& second) { char ch; ins ch; // discard init '(' ins second.f; ins ch; // discard comma ',' ins second.s; ins ch; // discard final '(' return ins; } ostream& operator<< (ostream& outs, const Pair& second) { outs << '('; outs << second.f; outs << ", " ;// I followed the Author's suggestion here. outs << second.s; outs << ")"; return outs; }

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• java nested for() loop throws ArrayIndexOutOfBoundsException

  - by Mike

  I'm working through a JPanel exercise in a Java book. I'm tasked with creating a 5x4 grid using GridLayout. When I loop through the container to add panels and buttons, the first add() throws the OOB exception. What am I doing wrong? package mineField; import java.awt.*; import javax.swing.*; @SuppressWarnings("serial") public class MineField extends JFrame { private final int WIDTH = 250; private final int HEIGHT = 120; private final int MAX_ROWS = 5; private final int MAX_COLUMNS = 4; public MineField() { super("Minefield"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Container mineFieldGrid = getContentPane(); mineFieldGrid.setLayout(new GridLayout(MAX_ROWS, MAX_COLUMNS)); // loop through arrays, add panels, then add buttons to panels. for (int i = 0; i < MAX_ROWS; i++) { JPanel[] rows = new JPanel[i]; mineFieldGrid.add(rows[i], rows[i].getName()); rows[i].setBackground(Color.blue); for (int j = 0; j < MAX_COLUMNS; j++) { JButton[] buttons = new JButton[i]; rows[i].add(buttons[j], buttons[j].getName()); } } mineFieldGrid.setSize(WIDTH, HEIGHT); mineFieldGrid.setVisible(true); } public int setRandomBomb(Container con) { int bombID; bombID = (int) (Math.random() * con.getComponentCount()); return bombID; } /** * @param args */ public static void main(String[] args) { //int randomBomb; //JButton bombLocation; MineField minePanel = new MineField(); //minePanel[randomBomb] = minePanel.setRandomBomb(minePanel); } } I'm sure I'm over-engineering a simple nested for loop. Since I'm new to Java, please be kind. I'm sure I'll return the favor some day.

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• Windows 7 inbuilt and 3rd party (de)fragmentation related queries

  - by Karan

  I have a pretty good idea of how files end up getting fragmented. That said, I just copied ~3,200 files of varying sizes (from a few KB to ~20GB) from an external USB HDD to an internal, freshly formatted (under Windows 7 x64), NTFS, 2TB, 5400RPM, WD, SATA, non-system (i.e. secondary) drive, filling it up 57%. Since it should have been very much possible for each file to have been stored in one contiguous block, I expected the drive to be fragmented not more than 1-2% at most after this rather lengthy exercise (unfortunately this older machine doesn't support USB 3.0). Windows 7's inbuilt defrag utility told me after a quick analysis that the drive was fragmented only 1% or so, which dovetailed neatly with my expectations. However, just out of curiosity I downloaded and ran the latest portable x64 version of Piriform's Defraggler, and was shocked to see the drive being reported as being ~85% fragmented! The portable version of Auslogics Disk Defrag also agreed with Defraggler, and both clearly expected to grind away for ~10 hours to completely defragment the drive. 1) How in blazes could the inbuilt and 3rd party defrag utils disagree so badly? I mean, 10-20% variance is probably understandable, but 1% and 85% are miles apart! This Engineering Windows 7 blog post states: In Windows XP, any file that is split into more than one piece is considered fragmented. Not so in Windows Vista if the fragments are large enough – the defragmentation algorithm was changed (from Windows XP) to ignore pieces of a file that are larger than 64MB. As a result, defrag in XP and defrag in Vista will report different amounts of fragmentation on a volume. ... [Please read the entire post so the quote is not taken out of context.] Could it simply be that the 3rd party defrag utils ignore this post-XP change and continue to use analysis algos similar to those XP used? 2) Assuming that the 3rd party utils aren't lying about the real extent of fragmentation (which Windows is downplaying post-XP), how could the files have even got fragmented so badly given they were just copied over afresh to an empty drive? 3) If vastly differing analysis algos explain the yawning gap, which do I believe? I'm no defrag fanatic for sure, but 85% is enough to make me seriously consider spending 10 hours defragging this drive. On the other hand, 1% reported by Windows' own defragger clearly implies that there is no cause for concern and defragging would actually have negative consequences (as per the post). Is Windows' assumption valid and should I just let it be, or will there be any noticeable performance gains after running one of the 3rd party utils for 10 hours straight? 4) I see that out of the box Windows 7 defrag is scheduled to run weekly. Does anyone know whether it defrags every single time, or only if its analysis reveals a fragmentation percentage over a set threshold? If the latter, what is this threshold and can it be changed, maybe via a Registry edit? Thanks for reading through (my first query on this wonderful site!) and for any helpful replies. Also, if you're answering question #3, please keep in mind that any speed increases post defragging with 3rd party utils vis-à-vis Windows' inbuilt program should not include pre-Vista (preferably pre-Win7) examples. Further, examples of programs that made your system boot faster won't help in this case, since this is a non-system drive (although one that'll still be used daily).

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• Solaris 11 Launch Blog Carnival Roundup

  - by constant

  Solaris 11 is here! And together with the official launch activities, a lot of Oracle and non-Oracle bloggers contributed helpful and informative blog articles to help your datacenter go to eleven. Here are some notable blog postings, sorted by category for your Solaris 11 blog-reading pleasure: Getting Started/Overview A lot of people speculated that the official launch of Solaris 11 would be on 11/11 (whatever way you want to turn it), but it actually happened two days earlier. Larry Wake himself offers 11 Reasons Why Oracle Solaris 11 11/11 Isn't Being Released on 11/11/11. Then, Larry goes on with a summary: Oracle Solaris 11: The First Cloud OS gives you a short and sweet rundown of what the major new features of Solaris 11 are. Jeff Victor has his own list of What's New in Oracle Solaris 11. A popular Solaris 11 meme is to write a blog post about 11 favourite features: Jim Laurent's 11 Reasons to Love Solaris 11, Darren Moffat's 11 Favourite Solaris 11 Features, Mike Gerdt's 11 of My Favourite Things! are just three examples of "11 Favourite Things..." type blog posts, I'm sure many more will follow... More official overview content for Solaris 11 is available from the Oracle Tech Network Solaris 11 Portal. Also, check out Rick Ramsey's blog post Solaris 11 Resources for System Administrators on the OTN Blog and his secret 5 Commands That Make Solaris Administration Easier post from the OTN Garage. (Automatic) Installation and the Image Packaging System (IPS) The brand new Image Packaging System (IPS) and the Automatic Installer (IPS), together with numerous other install/packaging/boot/patching features are among the most significant improvements in Solaris 11. But before installing, you may wonder whether Solaris 11 will support your particular set of hardware devices. Again, the OTN Garage comes to the rescue with Rick Ramsey's post How to Find Out Which Devices Are Supported By Solaris 11. Included is a useful guide to all the first steps to get your Solaris 11 system up and running. Tim Foster had a whole handful of blog posts lined up for the launch, teaching you everything you need to know about IPS but didn't dare to ask: The IPS System Repository, IPS Self-assembly - Part 1: Overlays and Part 2: Multiple Packages Delivering Configuration. Watch out for more IPS posts from Tim! If installing packages or upgrading your system from the net makes you uneasy, then you're not alone: Jim Laurent will tech you how Building a Solaris 11 Repository Without Network Connection will make your life easier. Many of you have already peeked into the future by installing Solaris 11 Express. If you're now wondering whether you can upgrade or whether a fresh install is necessary, then check out Alan Hargreaves's post Upgrading Solaris 11 Express b151a with support to Solaris 11. The trick is in upgrading your pkg(1M) first. Networking One of the first things to do after installing Solaris 11 (or any operating system for that matter), is to set it up for networking. Solaris 11 comes with the brand new "Network Auto-Magic" feature which can figure out everything by itself. For those cases where you want to exercise a little more control, Solaris 11 left a few people scratching their heads. Fortunately, Tschokko wrote up this cool blog post: Solaris 11 manual IPv4 & IPv6 configuration right after the launch ceremony. Thanks, Tschokko! And Milek points out a long awaited networking feature in Solaris 11 called Solaris 11 - hostmodel, which I know for a fact that many customers have looked forward to: How to "bind" a Solaris 11 system to a specific gateway for specific IP address it is using. Steffen Weiberle teaches us how to tune the Solaris 11 networking stack the proper way: ipadm(1M). No more fiddling with ndd(1M)! Check out his tutorial on Solaris 11 Network Tunables. And if you want to get even deeper into the networking stack, there's nothing better than DTrace. Alan Maguire teaches you in: DTracing TCP Congestion Control how to probe deeply into the Solaris 11 TCP/IP stack, the TCP congestion control part in particular. Don't miss his other DTrace and TCP related blog posts! DTrace And there we are: DTrace, the king of all observability tools. Long time DTrace veteran and co-author of The DTrace book*, Brendan Gregg blogged about Solaris 11 DTrace syscall provider changes. BTW, after you install Solaris 11, check out the DTrace toolkit which is installed by default in /usr/dtrace/DTT. It is chock full of handy DTrace scripts, many of which contributed by Brendan himself! Security Another big theme in Solaris 11, and one that is crucial for the success of any operating system in the Cloud is Security. Here are some notable posts in this category: Darren Moffat starts by showing us how to completely get rid of root: Completely Disabling Root Logins on Solaris 11. With no root user, there's one major entry point less to worry about. But that's only the start. In Immutable Zones on Encrypted ZFS, Darren shows us how to double the security of your services: First by locking them into the new Immutable Zones feature, then by encrypting their data using the new ZFS encryption feature. And if you're still missing sudo from your Linux days, Darren again has a solution: Password (PAM) caching for Solaris su - "a la sudo". If you're wondering how much compute power all this encryption will cost you, you're in luck: The Solaris X86 AESNI OpenSSL Engine will make sure you'll use your Intel's embedded crypto support to its fullest. And if you own a brand new SPARC T4 machine you're even luckier: It comes with its own SPARC T4 OpenSSL Engine. Dan Anderson's posts show how there really is now excuse not to encrypt any more... Developers Solaris 11 has a lot to offer to developers as well. Ali Bahrami has a series of blog posts that cover diverse developer topics: elffile: ELF Specific File Identification Utility, Using Stub Objects and The Stub Proto: Not Just For Stub Objects Anymore to name a few. BTW, if you're a developer and want to shape the future of Solaris 11, then Vijay Tatkar has a hint for you: Oracle (Sun Systems Group) is hiring! Desktop and Graphics Yes, Solaris 11 is a 100% server OS, but it can also offer a decent desktop environment, especially if you are a developer. Alan Coopersmith starts by discussing S11 X11: ye olde window system in today's new operating system, then Calum Benson shows us around What's new on the Solaris 11 Desktop. Even accessibility is a first-class citizen in the Solaris 11 user interface. Peter Korn celebrates: Accessible Oracle Solaris 11 - released! Performance Gone are the days of "Slowaris", when Solaris was among the few OSes that "did the right thing" while others cut corners just to win benchmarks. Today, Solaris continues doing the right thing, and it delivers the right performance at the same time. Need proof? Check out Brian's BestPerf blog with continuous updates from the benchmarking lab, including Recent Benchmarks Using Oracle Solaris 11! Send Me More Solaris 11 Launch Articles! These are just a few of the more interesting blog articles that came out around the Solaris 11 launch, I'm sure there are many more! Feel free to post a comment below if you find a particularly interesting blog post that hasn't been listed so far and share your enthusiasm for Solaris 11! *Affiliate link: Buy cool stuff and support this blog at no extra cost. We both win! var flattr_uid = '26528'; var flattr_tle = 'Solaris 11 Launch Blog Carnival Roundup'; var flattr_dsc = '<strong>Solaris 11 is here!</strong>And together with the official launch activities, a lot of Oracle and non-Oracle bloggers contributed helpful and informative blog articles to help your datacenter <a href="http://en.wikipedia.org/wiki/Up_to_eleven">go to eleven</a>.Here are some notable blog postings, sorted by category for your Solaris 11 blog-reading pleasure:'; var flattr_tag = 'blogging,digest,Oracle,Solaris,solaris,solaris 11'; var flattr_cat = 'text'; var flattr_url = 'http://constantin.glez.de/blog/2011/11/solaris-11-launch-blog-carnival-roundup'; var flattr_lng = 'en_GB'

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• Using a "white list" for extracting terms for Text Mining

  - by [email protected]

  In Part 1 of my post on "Generating cluster names from a document clustering model" (part 1, part 2, part 3), I showed how to build a clustering model from text documents using Oracle Data Miner, which automates preparing data for text mining. In this process we specified a custom stoplist and lexer and relied on Oracle Text to identify important terms.  However, there is an alternative approach, the white list, which uses a thesaurus object with the Oracle Text CTXRULE index to allow you to specify the important terms. INTRODUCTIONA stoplist is used to exclude, i.e., black list, specific words in your documents from being indexed. For example, words like a, if, and, or, and but normally add no value when text mining. Other words can also be excluded if they do not help to differentiate documents, e.g., the word Oracle is ubiquitous in the Oracle product literature. One problem with stoplists is determining which words to specify. This usually requires inspecting the terms that are extracted, manually identifying which ones you don't want, and then re-indexing the documents to determine if you missed any. Since a corpus of documents could contain thousands of words, this could be a tedious exercise. Moreover, since every word is considered as an individual token, a term excluded in one context may be needed to help identify a term in another context. For example, in our Oracle product literature example, the words "Oracle Data Mining" taken individually are not particular helpful. The term "Oracle" may be found in nearly all documents, as with the term "Data." The term "Mining" is more unique, but could also refer to the Mining industry. If we exclude "Oracle" and "Data" by specifying them in the stoplist, we lose valuable information. But it we include them, they may introduce too much noise. Still, when you have a broad vocabulary or don't have a list of specific terms of interest, you rely on the text engine to identify important terms, often by computing the term frequency - inverse document frequency metric. (This is effectively a weight associated with each term indicating its relative importance in a document within a collection of documents. We'll revisit this later.) The results using this technique is often quite valuable. As noted above, an alternative to the subtractive nature of the stoplist is to specify a white list, or a list of terms--perhaps multi-word--that we want to extract and use for data mining. The obvious downside to this approach is the need to specify the set of terms of interest. However, this may not be as daunting a task as it seems. For example, in a given domain (Oracle product literature), there is often a recognized glossary, or a list of keywords and phrases (Oracle product names, industry names, product categories, etc.). Being able to identify multi-word terms, e.g., "Oracle Data Mining" or "Customer Relationship Management" as a single token can greatly increase the quality of the data mining results. The remainder of this post and subsequent posts will focus on how to produce a dataset that contains white list terms, suitable for mining. CREATING A WHITE LIST We'll leverage the thesaurus capability of Oracle Text. Using a thesaurus, we create a set of rules that are in effect our mapping from single and multi-word terms to the tokens used to represent those terms. For example, "Oracle Data Mining" becomes "ORACLEDATAMINING." First, we'll create and populate a mapping table called my_term_token_map. All text has been converted to upper case and values in the TERM column are intended to be mapped to the token in the TOKEN column. TERM                                TOKEN DATA MINING                         DATAMINING ORACLE DATA MINING                  ORACLEDATAMINING 11G                                 ORACLE11G JAVA                                JAVA CRM                                 CRM CUSTOMER RELATIONSHIP MANAGEMENT    CRM ... Next, we'll create a thesaurus object my_thesaurus and a rules table my_thesaurus_rules: CTX_THES.CREATE_THESAURUS('my_thesaurus', FALSE); CREATE TABLE my_thesaurus_rules (main_term     VARCHAR2(100),                                  query_string  VARCHAR2(400)); We next populate the thesaurus object and rules table using the term token map. A cursor is defined over my_term_token_map. As we iterate over  the rows, we insert a synonym relationship 'SYN' into the thesaurus. We also insert into the table my_thesaurus_rules the main term, and the corresponding query string, which specifies synonyms for the token in the thesaurus. DECLARE   cursor c2 is     select token, term     from my_term_token_map; BEGIN   for r_c2 in c2 loop     CTX_THES.CREATE_RELATION('my_thesaurus',r_c2.token,'SYN',r_c2.term);     EXECUTE IMMEDIATE 'insert into my_thesaurus_rules values                        (:1,''SYN(' || r_c2.token || ', my_thesaurus)'')'     using r_c2.token;   end loop; END; We are effectively inserting the token to return and the corresponding query that will look up synonyms in our thesaurus into the my_thesaurus_rules table, for example:     'ORACLEDATAMINING'        SYN ('ORACLEDATAMINING', my_thesaurus)At this point, we create a CTXRULE index on the my_thesaurus_rules table: create index my_thesaurus_rules_idx on        my_thesaurus_rules(query_string)        indextype is ctxsys.ctxrule; In my next post, this index will be used to extract the tokens that match each of the rules specified. We'll then compute the tf-idf weights for each of the terms and create a nested table suitable for mining.

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• Web Self Service installation on Windows

  - by Rajesh Sharma

  Web Self Service (WSS) installation on windows is pretty straight forward but you might face some issues if deployed under tomcat. Here's a step-by-step guide to install Oracle Utilities Web Self Service on windows.   Below installation steps are done on: Oracle Utilities Framework version 2.2.0 Oracle Utilities Application - Customer Care & Billing version 2.2.0 Application server - Apache Tomcat 6.0.13 on default port 6500 Other settings include: SPLBASE = C:\spl\CCBDEMO22 SPLENVIRON = CCBV22 SPLWAS = TCAT   Follow these steps for a Web Self Service installation on windows: Download Web Self Service application from edelivery.   Copy the delivery file Release-SelfService-V2.2.0.zip from the Oracle Utilities Customer Care and Billing version 2.2.0 Web Self Service folder on the installation media to a directory on your Windows box where you would like to install the application, in our case it's a temporary folder C:\wss_temp.   Setup application environment, execute splenviron.cmd -e <ENVIRON_NAME>   Create base folder for Self Service application named SelfService under %SPLEBASE%\splapp\applications   Install Oracle Utilities Web Self Service   C:\wss_temp\Release-SelfService-V2.2.0>install.cmd -d %SPLEBASE%\splapp\applications\SelfService   Web Self Service installation menu. Populate environment values for each item.   ******************************************************** Pick your installation options: ******************************************************** 1. Destination directory name for installation.             | C:\spl\CCBDEMO22\splapp\applications\SelfService 2. Web Server Host.                                         | CCBV22 3. Web Server Port Number.                                  | 6500 4. Mail SMTP Host.                                          | CCBV22 5. Top Product Installation directory.                      | C:\spl\CCBDEMO22 6.     Web Application Server Type.                         | TCAT 7.     When OAS: SPLWeb OC4J instance name is required.     | OC4J1 8.     When WAS: SPLWeb server instance name is required.   | server1   P. Process the installation. Each item in the above list should be configured for a successful installation. Choose option to configure or (P) to process the installation:  P   Option 7 and Option 8 can be ignored for TCAT.   Above step installs SelfService.war file in the destination directory. We need to explode this war file. Change directory to the installation destination folder, and   C:\spl\CCBDEMO22\splapp\applications\SelfService>jar -xf SelfService.war   Review SelfServiceConfig.properties and CMSelfServiceConfig.properties. Change any properties value within the file specific to your installation/site. Generally default settings apply, for this exercise assumes that WEB user already exists in your application database.   For more information on property file customization, refer to Oracle Utilities Web Self Service Configuration section in Customer Care & Billing Installation Guide.   Add context entry in server.xml located under tomcat-base folder C:\spl\CCBDEMO22\product\tomcatBase\conf   ... <!-- SPL Context -->           <Context path="" docBase="C:/spl/CCBDEMO22/splapp/applications/root" debug="0" privileged="true"/>           <Context path="/appViewer" docBase="C:/spl/CCBDEMO22/splapp/applications/appViewer" debug="0" privileged="true"/>           <Context path="/help" docBase="C:/spl/CCBDEMO22/splapp/applications/help" debug="0" privileged="true"/>           <Context path="/XAIApp" docBase="C:/spl/CCBDEMO22/splapp/applications/XAIApp" debug="0" privileged="true"/>           <Context path="/SelfService" docBase="C:/spl/CCBDEMO22/splapp/applications/SelfService" debug="0" privileged="true"/> ...   Add User in tomcat-users.xml file located under tomcat-base folder C:\spl\CCBDEMO22\product\tomcatBase\conf   <user username="WEB" password="selfservice" roles="cisusers"/>   Note the password is "selfservice", this is the default password set within the SelfServiceConfig.properties file with base64 encoding.   Restart the application (spl.cmd stop | start)   12.  Although Apache Tomcat version 6.0.13 does not come with the admin pack, you can verify whether SelfService application is loaded and running, go to following URL http://server:port/manager/list, in our case it'll be http://ccbv22:6500/manager/list Following output will be displayed   OK - Listed applications for virtual host localhost /admin:running:0:C:/tomcat/apache-tomcat-6.0.13/webapps/ROOT/admin /XAIApp:running:0:C:/spl/CCBDEMO22/splapp/applications/XAIApp /host-manager:running:0:C:/tomcat/apache-tomcat-6.0.13/webapps/host-manager /SelfService:running:0:C:/spl/CCBDEMO22/splapp/applications/SelfService /appViewer:running:0:C:/spl/CCBDEMO22/splapp/applications/appViewer /manager:running:1:C:/tomcat/apache-tomcat-6.0.13/webapps/manager /help:running:0:C:/spl/CCBDEMO22/splapp/applications/help /:running:0:C:/spl/CCBDEMO22/splapp/applications/root   Also ensure that the XAIApp is running.   Run Oracle Utilities Web Self Service application http://server:port/SelfService in our case it'll be  http://ccbv22:6500/SelfService   Still doesn't work? And you get '503 HTTP response' at the time of customer registration?     This is because XAI service is still unavailable. There is initialize.waittime set for a default value of 90 seconds for the XAI Application to come up.   Remember WSS uses XAI to perform actions/validations on the CC&B database.  

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• SQL SERVER – Introduction to SQL Server 2014 In-Memory OLTP

  - by Pinal Dave

  In SQL Server 2014 Microsoft has introduced a new database engine component called In-Memory OLTP aka project “Hekaton” which is fully integrated into the SQL Server Database Engine. It is optimized for OLTP workloads accessing memory resident data. In-memory OLTP helps us create memory optimized tables which in turn offer significant performance improvement for our typical OLTP workload. The main objective of memory optimized table is to ensure that highly transactional tables could live in memory and remain in memory forever without even losing out a single record. The most significant part is that it still supports majority of our Transact-SQL statement. Transact-SQL stored procedures can be compiled to machine code for further performance improvements on memory-optimized tables. This engine is designed to ensure higher concurrency and minimal blocking. In-Memory OLTP alleviates the issue of locking, using a new type of multi-version optimistic concurrency control. It also substantially reduces waiting for log writes by generating far less log data and needing fewer log writes. Points to remember Memory-optimized tables refer to tables using the new data structures and key words added as part of In-Memory OLTP. Disk-based tables refer to your normal tables which we used to create in SQL Server since its inception. These tables use a fixed size 8 KB pages that need to be read from and written to disk as a unit. Natively compiled stored procedures refer to an object Type which is new and is supported by in-memory OLTP engine which convert it into machine code, which can further improve the data access performance for memory –optimized tables. Natively compiled stored procedures can only reference memory-optimized tables, they can’t be used to reference any disk –based table. Interpreted Transact-SQL stored procedures, which is what SQL Server has always used. Cross-container transactions refer to transactions that reference both memory-optimized tables and disk-based tables. Interop refers to interpreted Transact-SQL that references memory-optimized tables. Using In-Memory OLTP In-Memory OLTP engine has been available as part of SQL Server 2014 since June 2013 CTPs. Installation of In-Memory OLTP is part of the SQL Server setup application. The In-Memory OLTP components can only be installed with a 64-bit edition of SQL Server 2014 hence they are not available with 32-bit editions. Creating Databases Any database that will store memory-optimized tables must have a MEMORY_OPTIMIZED_DATA filegroup. This filegroup is specifically designed to store the checkpoint files needed by SQL Server to recover the memory-optimized tables, and although the syntax for creating the filegroup is almost the same as for creating a regular filestream filegroup, it must also specify the option CONTAINS MEMORY_OPTIMIZED_DATA. Here is an example of a CREATE DATABASE statement for a database that can support memory-optimized tables: CREATE DATABASE InMemoryDB ON PRIMARY(NAME = [InMemoryDB_data], FILENAME = 'D:\data\InMemoryDB_data.mdf', size=500MB), FILEGROUP [SampleDB_mod_fg] CONTAINS MEMORY_OPTIMIZED_DATA (NAME = [InMemoryDB_mod_dir], FILENAME = 'S:\data\InMemoryDB_mod_dir'), (NAME = [InMemoryDB_mod_dir], FILENAME = 'R:\data\InMemoryDB_mod_dir') LOG ON (name = [SampleDB_log], Filename='L:\log\InMemoryDB_log.ldf', size=500MB) COLLATE Latin1_General_100_BIN2; Above example code creates files on three different drives (D:  S: and R:) for the data files and in memory storage so if you would like to run this code kindly change the drive and folder locations as per your convenience. Also notice that binary collation was specified as Windows (non-SQL). BIN2 collation is the only collation support at this point for any indexes on memory optimized tables. It is also possible to add a MEMORY_OPTIMIZED_DATA file group to an existing database, use the below command to achieve the same. ALTER DATABASE AdventureWorks2012 ADD FILEGROUP hekaton_mod CONTAINS MEMORY_OPTIMIZED_DATA; GO ALTER DATABASE AdventureWorks2012 ADD FILE (NAME='hekaton_mod', FILENAME='S:\data\hekaton_mod') TO FILEGROUP hekaton_mod; GO Creating Tables There is no major syntactical difference between creating a disk based table or a memory –optimized table but yes there are a few restrictions and a few new essential extensions. Essentially any memory-optimized table should use the MEMORY_OPTIMIZED = ON clause as shown in the Create Table query example. DURABILITY clause (SCHEMA_AND_DATA or SCHEMA_ONLY) Memory-optimized table should always be defined with a DURABILITY value which can be either SCHEMA_AND_DATA or  SCHEMA_ONLY the former being the default. A memory-optimized table defined with DURABILITY=SCHEMA_ONLY will not persist the data to disk which means the data durability is compromised whereas DURABILITY= SCHEMA_AND_DATA ensures that data is also persisted along with the schema. Indexing Memory Optimized Table A memory-optimized table must always have an index for all tables created with DURABILITY= SCHEMA_AND_DATA and this can be achieved by declaring a PRIMARY KEY Constraint at the time of creating a table. The following example shows a PRIMARY KEY index created as a HASH index, for which a bucket count must also be specified. CREATE TABLE Mem_Table ( [Name] VARCHAR(32) NOT NULL PRIMARY KEY NONCLUSTERED HASH WITH (BUCKET_COUNT = 100000), [City] VARCHAR(32) NULL, [State_Province] VARCHAR(32) NULL, [LastModified] DATETIME NOT NULL, ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA); Now as you can see in the above query example we have used the clause MEMORY_OPTIMIZED = ON to make sure that it is considered as a memory optimized table and not just a normal table and also used the DURABILITY Clause= SCHEMA_AND_DATA which means it will persist data along with metadata and also you can notice this table has a PRIMARY KEY mentioned upfront which is also a mandatory clause for memory-optimized tables. We will talk more about HASH Indexes and BUCKET_COUNT in later articles on this topic which will be focusing more on Row and Index storage on Memory-Optimized tables. So stay tuned for that as well. Now as we covered the basics of Memory Optimized tables and understood the key things to remember while using memory optimized tables, let’s explore more using examples to understand the Performance gains using memory-optimized tables. I will be using the database which i created earlier in this article i.e. InMemoryDB in the below Demo Exercise. USE InMemoryDB GO -- Creating a disk based table CREATE TABLE dbo.Disktable ( Id INT IDENTITY, Name CHAR(40) ) GO CREATE NONCLUSTERED INDEX IX_ID ON dbo.Disktable (Id) GO -- Creating a memory optimized table with similar structure and DURABILITY = SCHEMA_AND_DATA CREATE TABLE dbo.Memorytable_durable ( Id INT NOT NULL PRIMARY KEY NONCLUSTERED Hash WITH (bucket_count =1000000), Name CHAR(40) ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA) GO -- Creating an another memory optimized table with similar structure but DURABILITY = SCHEMA_Only CREATE TABLE dbo.Memorytable_nondurable ( Id INT NOT NULL PRIMARY KEY NONCLUSTERED Hash WITH (bucket_count =1000000), Name CHAR(40) ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_only) GO -- Now insert 100000 records in dbo.Disktable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Disktable(Name) VALUES('sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END -- Do the same inserts for Memory table dbo.Memorytable_durable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Memorytable_durable VALUES(@i_t, 'sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END -- Now finally do the same inserts for Memory table dbo.Memorytable_nondurable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Memorytable_nondurable VALUES(@i_t, 'sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END The above 3 Inserts took 1.20 minutes, 54 secs, and 2 secs respectively to insert 100000 records on my machine with 8 Gb RAM. This proves the point that memory-optimized tables can definitely help businesses achieve better performance for their highly transactional business table and memory- optimized tables with Durability SCHEMA_ONLY is even faster as it does not bother persisting its data to disk which makes it supremely fast. Koenig Solutions is one of the few organizations which offer IT training on SQL Server 2014 and all its updates. Now, I leave the decision on using memory_Optimized tables on you, I hope you like this article and it helped you understand  the fundamentals of IN-Memory OLTP . Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Koenig

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