Search Results

Search found 90546 results on 3622 pages for 'code optimization'.

Page 16/3622 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

• Algorithm for generating an array of non-equal costs for a transport problem optimization

  - by Carlos

  I have an optimizer that solves a transportation problem, using a cost matrix of all the possible paths. The optimiser works fine, but if two of the costs are equal, the solution contains one more path that the minimum number of paths. (Think of it as load balancing routers; if two routes are same cost, you'll use them both.) I would like the minimum number of routes, and to do that I need a cost matrix that doesn't have two costs that are equal within a certain tolerance. At the moment, I'm passing the cost matrix through a baking function which tests every entry for equality to each of the other entries, and moves it a fixed percentage if it matches. However, this approach seems to require N^2 comparisons, and if the starting values are all the same, the last cost will be r^N bigger. (r is the arbitrary fixed percentage). Also there is the problem that by multiplying by the percentage, you end up on top of another value. So the problem seems to have an element of recursion, or at least repeated checking, which bloats the code. The current implementation is basically not very good (I won't paste my GOTO-using code here for you all to mock), and I'd like to improve it. Is there a name for what I'm after, and is there a standard implementation? Example: {1,1,2,3,4,5} (tol = 0.05) becomes {1,1.05,2,3,4,5}

  Read the article

• Optimization of Function with Dictionary and Zip()

  - by eWizardII

  Hello, I have the following function: def filetxt(): word_freq = {} lvl1 = [] lvl2 = [] total_t = 0 users = 0 text = [] for l in range(0,500): # Open File if os.path.exists("C:/Twitter/json/user_" + str(l) + ".json") == True: with open("C:/Twitter/json/user_" + str(l) + ".json", "r") as f: text_f = json.load(f) users = users + 1 for i in range(len(text_f)): text.append(text_f[str(i)]['text']) total_t = total_t + 1 else: pass # Filter occ = 0 import string for i in range(len(text)): s = text[i] # Sample string a = re.findall(r'(RT)',s) b = re.findall(r'(@)',s) occ = len(a) + len(b) + occ s = s.encode('utf-8') out = s.translate(string.maketrans("",""), string.punctuation) # Create Wordlist/Dictionary word_list = text[i].lower().split(None) for word in word_list: word_freq[word] = word_freq.get(word, 0) + 1 keys = word_freq.keys() numbo = range(1,len(keys)+1) WList = ', '.join(keys) NList = str(numbo).strip('[]') WList = WList.split(", ") NList = NList.split(", ") W2N = dict(zip(WList, NList)) for k in range (0,len(word_list)): word_list[k] = W2N[word_list[k]] for i in range (0,len(word_list)-1): lvl1.append(word_list[i]) lvl2.append(word_list[i+1]) I have used the profiler to find that it seems the greatest CPU time is spent on the zip() function and the join and split parts of the code, I'm looking to see if there is any way I have overlooked that I could potentially clean up the code to make it more optimized, since the greatest lag seems to be in how I am working with the dictionaries and the zip() function. Any help would be appreciated thanks!

  Read the article

• compile time if && return string reference optimization

  - by Truncheon

  Hi. I'm writing a series classes that inherit from a base class using virtual. They are INT, FLOAT and STRING objects that I want to use in a scripting language. I'm trying to implement weak typing, but I don't want STRING objects to return copies of themselves when used in the following way (instead I would prefer to have a reference returned which can be used in copying): a = "hello "; b = "world"; c = a + b; I have written the following code as a mock example: #include <iostream> #include <string> #include <cstdio> #include <cstdlib> std::string dummy("<int object cannot return string reference>"); struct BaseImpl { virtual bool is_string() = 0; virtual int get_int() = 0; virtual std::string get_string_copy() = 0; virtual std::string const& get_string_ref() = 0; }; struct INT : BaseImpl { int value; INT(int i = 0) : value(i) { std::cout << "constructor called\n"; } INT(BaseImpl& that) : value(that.get_int()) { std::cout << "copy constructor called\n"; } bool is_string() { return false; } int get_int() { return value; } std::string get_string_copy() { char buf[33]; sprintf(buf, "%i", value); return buf; } std::string const& get_string_ref() { return dummy; } }; struct STRING : BaseImpl { std::string value; STRING(std::string s = "") : value(s) { std::cout << "constructor called\n"; } STRING(BaseImpl& that) { if (that.is_string()) value = that.get_string_ref(); else value = that.get_string_copy(); std::cout << "copy constructor called\n"; } bool is_string() { return true; } int get_int() { return atoi(value.c_str()); } std::string get_string_copy() { return value; } std::string const& get_string_ref() { return value; } }; struct Base { BaseImpl* impl; Base(BaseImpl* p = 0) : impl(p) {} ~Base() { delete impl; } }; int main() { Base b1(new INT(1)); Base b2(new STRING("Hello world")); Base b3(new INT(*b1.impl)); Base b4(new STRING(*b2.impl)); std::cout << "\n"; std::cout << b1.impl->get_int() << "\n"; std::cout << b2.impl->get_int() << "\n"; std::cout << b3.impl->get_int() << "\n"; std::cout << b4.impl->get_int() << "\n"; std::cout << "\n"; std::cout << b1.impl->get_string_ref() << "\n"; std::cout << b2.impl->get_string_ref() << "\n"; std::cout << b3.impl->get_string_ref() << "\n"; std::cout << b4.impl->get_string_ref() << "\n"; std::cout << "\n"; std::cout << b1.impl->get_string_copy() << "\n"; std::cout << b2.impl->get_string_copy() << "\n"; std::cout << b3.impl->get_string_copy() << "\n"; std::cout << b4.impl->get_string_copy() << "\n"; return 0; } It was necessary to add an if check in the STRING class to determine whether its safe to request a reference instead of a copy: Script code: a = "test"; b = a; c = 1; d = "" + c; /* not safe to request reference by standard */ C++ code: STRING(BaseImpl& that) { if (that.is_string()) value = that.get_string_ref(); else value = that.get_string_copy(); std::cout << "copy constructor called\n"; } If was hoping there's a way of moving that if check into compile time, rather than run time.

  Read the article

• SQL query performance optimization (TimesTen)

  - by Sergey Mikhanov

  Hi community, I need some help with TimesTen DB query optimization. I made some measures with Java profiler and found the code section that takes most of the time (this code section executes the SQL query). What is strange that this query becomes expensive only for some specific input data. Here’s the example. We have two tables that we are querying, one represents the objects we want to fetch (T_PROFILEGROUP), another represents the many-to-many link from some other table (T_PROFILECONTEXT_PROFILEGROUPS). We are not querying linked table. These are the queries that I executed with DB profiler running (they are the same except for the ID): Command> select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; < 1169655247309537280 > < 1169655249792565248 > < 1464837997699399681 > 3 rows found. Command> select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; < 1169655247309537280 > 1 row found. This is what I have in the profiler: 12:14:31.147 1 SQL 2L 6C 10825P Preparing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272 12:14:31.147 2 SQL 4L 6C 10825P sbSqlCmdCompile ()(E): (Found already compiled version: refCount:01, bucket:47) cmdType:100, cmdNum:1146695. 12:14:31.147 3 SQL 4L 6C 10825P Opening: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.147 4 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.148 5 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.148 6 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.228 7 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.228 8 SQL 4L 6C 10825P Closing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:35.243 9 SQL 2L 6C 10825P Preparing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928 12:14:35.243 10 SQL 4L 6C 10825P sbSqlCmdCompile ()(E): (Found already compiled version: refCount:01, bucket:44) cmdType:100, cmdNum:1146697. 12:14:35.243 11 SQL 4L 6C 10825P Opening: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 12 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 13 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 14 SQL 4L 6C 10825P Closing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; It’s clear that the first query took almost 100ms, while the second was executed instantly. It’s not about queries precompilation (the first one is precompiled too, as same queries happened earlier). We have DB indices for all columns used here: T_PROFILEGROUP.M_ID, T_PROFILECONTEXT_PROFILEGROUPS.M_ID_OID and T_PROFILECONTEXT_PROFILEGROUPS.M_ID_EID. My questions are: Why querying the same set of tables yields such a different performance for different parameters? Which indices are involved here? Is there any way to improve this simple query and/or the DB to make it faster? UPDATE: to give the feeling of size: Command> select count(*) from T_PROFILEGROUP; < 183840 > 1 row found. Command> select count(*) from T_PROFILECONTEXT_PROFILEGROUPS; < 2279104 > 1 row found.

  Read the article

• Which libraries use the "We Know Where You Live" optimization for std::make_shared?

  - by KnowItAllWannabe

  Over two years ago, Stephan T. Lavavej described a space-saving optimization he implemented in Microsoft's implementation of std::make_shared, and I know from speaking with him that Microsoft has nothing against other library implementations adopting this optimization. If you know for sure whether other libraries (e.g., for Gnu C++, Clang, Intel C++, plus Boost (for boost::make_shared)) have adopted this implementation, please contribute an answer. I don't have ready access to that many make_shared implementations, nor am I wild about digging into the bowels of the ones I have to see if they've implemented the WKWYL optimization, but I'm hoping that SO readers know the answers for some libraries off-hand. I know from looking at the code that as of Boost 1.52, the WKWYL optimization had not been implemented, but Boost is now up to version 1.55. Note that this optimization is different from std::make_shared's ability to avoid a dedicated heap allocation for the reference count used by std::shared_ptr. For a discussion of the difference between WKWYL and that optimication, consult this question.

  Read the article

• Optimizing mathematics on arrays of floats in Ada 95 with GNATC

  - by mat_geek

  Consider the bellow code. This code is supposed to be processing data at a fixed rate, in one second batches, It is part of an overal system and can't take up too much time. When running over 100 lots of 1 seconds worth of data the program takes 35 seconds; or 35%. How do I improce the code to get the processing time down to a minimum? The code will be running on an Intel Pentium-M which is a P3 with SSE2. package FF is new Ada.Numerics.Generic_Elementary_Functions(Float); N : constant Integer := 820; type A is array(1 .. N) of Float; type A3 is array(1 .. 3) of A; procedure F(state : in out A3; result : out A3; l : in A; r : in A) is s : Float; t : Float; begin for i in 1 .. N loop t := l(i) + r(i); t := t / 2.0; state(1)(i) := t; state(2)(i) := t * 0.25 + state(2)(i) * 0.75; state(3)(i) := t * 1.0 /64.0 + state(2)(i) * 63.0 /64.0; for r in 1 .. 3 loop s := state(r)(i); t := FF."**"(s, 6.0) + 14.0; if t > MAX then t := MAX; elsif t < MIN then t := MIN; end if; result(r)(i) := FF.Log(t, 2.0); end loop; end loop; end;

  Read the article

• When to do code reviews when doing continuous integration?

  - by SpecialEd

  We are trying to switch to a continuous integration environment but are not sure when to do code reviews. From what I've read of continuous integration, we should be attempting to check in code as often as multiple times a day. I assume, this even means for features that are not yet complete. So the question is, when do we do the code reviews? We can't do it before we check in the code, because that would slow down the process where we will not be able to do daily checkins, let alone multiple checkins per day. Also, if the code we are checking in merely compiles but is not feature complete, doing a code review then is pointless, as most code reviews are best done as the feature is finalized. Does this mean we should do code reviews when a feature is completed, but that unreviewed code will get into the repository?

  Read the article

• Richmond Code Camp 2010.1

  - by andyleonard

  I can't believe it - Richmond Code Camp 2010.1 is less than two weeks away! Once again, the leadership team has outdone themselves. We have a bunch of great speakers, 9 tracks, 45 sessions - there's something for everyone. If you're going to be in the area and are interested, register today. :{> Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!...(read more)

  Read the article

• Clean Code says to avoid protected variables

  - by Matsemann

  I have a question to a statement in Clean Code. I don't fully understand the reasoning to why we should avoid protected variables. It's from the chapter about Formatting, section about Vertical Distance: Concepts that are closely related should be kept vertically close to each other. Clearly this rule doesn't work for concepts that belong in separate files. But then closely related concepts should not be separated into different files unless you have a very good reason. Indeed, this is one of the reasons that protected variables should be avoided.

  Read the article

• Extended Events Code Generator v1.001 - A Quick Fix

  - by Adam Machanic

  If you're one of the estimated 3-5 people who've downloaded and are using my XE Code Generator , please note that version 1.000 has a small bug: text data (such as query text) larger than 8000 bytes is truncated. I've fixed this issue and am pleased to present version 1.001, attached to this post. Enjoy, and stay tuned for slightly more interesting enhancements! Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!...(read more)

  Read the article

• SQL Query Builder/Designer and code Formating

  - by DavRob60

  I write SQL query every now and then, I could easily write them freehand, but sometimes I do create SQL queries using SQL Query Designers for various reason. (I wont start to enumerate them here and/or argue about their usefulness, so let's just say they are sometime useful.) Anyway, I currently use 2 Query Designers : SQL server management studio's Query Designer. Visual Studio 2010's Query Builder (must often within the Table adapter Query Configuration Wizard.) There's something I hate about those two (I don't know about the others), it's the way they throw away my Code formatting of SQL queries after an edit. Is there any way to configure something to automatically reformat the SQL output or is there any external tool/plug-in that I could use to do that job?

  Read the article

• Presenting at Roanoke Code Camp Saturday!

  - by andyleonard

  Introduction I am honored to once again be selected to present at Roanoke Code Camp ! An Introductory Topic One of my presentations is titled "I See a Control Flow Tab. Now What?" It's a Level 100 talk for those wishing to learn how to build their very first SSIS package. This highly-interactive, demo-intense presentation is for beginners and developers just getting started with SSIS. Attend and learn how to build SSIS packages from the ground up . Designing an SSIS Framework I'm also presenting...(read more)

  Read the article

• Coding standards in programming?

  - by vicky

  I am an WordPress Plugin Developer. I am not sure how to follow the coding standard while creating a plugin of wordpress. I check with some of the plugins like woocommerce and All in one SEO Plugin in that they are maintaining the proper coding standard. Basically I am Using the NetBeans IDE. Is it possible to make the proper space and coding standards in that IDE. I am Wondering to View his code is very neat and clean. How can i do this or how they are maintaining this. Anyone suggest me to make the wordpress plugin with well coding standards. Thanks, vicky

  Read the article

• Who owns code if its written by one person with another person directing [on hold]

  - by user136226

  I have an Issue that I need some info on. Basically what Im looking to find out is if I create software,and someone else gives me direction on what they want the software to look like,e.g. an image here,this font of text and it must behave in a certain way. Also some of the code was not developed on my computer and there is no official agreement in place. Not looking to screw anyone over here but need to protect myself if things go sour. Do I own the software or is it jointly owned? Thanks

  Read the article

• Do you think code is self documenting?

  - by Desolate Planet

  This is a question that was put to me many years ago as a gradute in a job interview and it's kind of picked at my brain now and again and I've never really found a good answer that satisfies me. The interviewer in question was looking for a black and white answer, there was no middle ground. I never got the chance to ask about the rationale behind the question, but I'm curious why that question would be put to a developer and what you would learn from a yes or no answer? From my own point of view, I can read Java, Python, Delphi etc, but if my manager comes up to me and asks me how far along in a project I am and I say "The code is 80% complete" (and before you start shooting me down, I've heard this uttered in a couple of offices by developers), how exactly is that self documenting? Apologies if this question seems strange, but I'd rather ask and get some opinions on it to gain a better understanding of why it would be put to someone in an interview.

  Read the article

• Single or multiple return statements in a function [on hold]

  - by Juan Carlos Coto

  When writing a function that can have several different return values, particularly when different branches of code return different values, what is the cleanest or sanest way of returning? Please note the following are really contrived examples meant only to illustrate different styles. Example 1: Single return def my_function(): if some_condition: return_value = 1 elif another_condition: return_value = 2 else: return_value = 3 return return_value Example 2: Multiple returns def my_function(): if some_condition: return 1 elif another_condition: return 2 else: return 3 The second example seems simpler and is perhaps more readable. The first one, however, might describe the overall logic a bit better (the conditions affect the assignment of the value, not whether it's returned or not). Is the second way preferable to the first? Why?

  Read the article

• Shouldn't we count characters of code and comments instead of lines of code and comments? [closed]

  - by Gabriel

  Counting lines of code and comments is sometimes bogus, since most of what we write may be written in one or more lines, depending column count limitations, screen size, style and so forth. Since the commonly used languages (say C, C++, C# and Java) are free-form, wouldn't it be more clever to count characters instead? Edit: I'm not considering LOC-oriented programming where coders try to artificially match requirements by adding irrelevant comments or using multiple lines where less would be enough (or the opposite). I'm interested in better metrics that would be independent of coding style, to be used by honest programmers.

  Read the article

• Do you think code is self documenting?

  - by Desolate Planet

  This is a question that was put to me many years ago as a gradute in a job interview and it's nagged at my brain now and again and I've never really found a good answer that satisfied me. The interviewer in question was looking for a black and white answer, there was no middle ground. I never got the chance to ask about the rationale behind the question, but I'm curious why that question would be put to a developer and what you would learn from a yes or no answer? From my own point of view, I can read Java, Python, Delphi etc, but if my manager comes up to me and asks me how far along in a project I am and I say "The code is 80% complete" (and before you start shooting me down, I've heard this uttered in a couple of offices by developers), how exactly is that self documenting? Apologies if this question seems strange, but I'd rather ask and get some opinions on it to gain a better understanding of why it would be put to someone in an interview.

  Read the article

• Better control on code updates

  - by yes123

  I will briefly explain my situation. I have a website in PHP, this website is powered by a custom framework + some "plug-in" made ad hoc for it. I am the only developer of this. Until now I just test locally any changes than I upload the php files via FTP. I don't feel confortable anymore with this. The code base has grown quite a lot and I need some sort of system that helps to keep track of changes (line by line) and can restore to an old version easly if something goes wrong. Are there any good solution for this? Note: I never used something like version control or subversion because I think they are too much for this situation (I am the only developer and I just need basic feature) Note2: Something with a nice web interface would be perfect, I can pay for a good service too As now I found: http://beanstalkapp.com/ http://github.com/ http://www.codespaces.com/ http://codesion.com/ https://bitbucket.org/

  Read the article

• Peer code review for full application

  - by bswinnerton

  My sincerest apologies if this is the wrong place to post something like this, but this seemed like the best fit. I was wondering if there are any websites or resources for a full site peer code review. I'm new to Ruby specifically and want to make sure that my logic is following the overall best standards. I've pieced together multiple different tutorials and I feel like while my understanding is getting better, it'd be great if the overall structure of such an application could be critiqued, and for someone that doesn't really know another Ruby developer - I find that I've run into a roadblock and don't want to develop bad habits now.

  Read the article

• How to prevent code from leaking outside work?

  - by AeroCross

  I'm working on an institution that has a really strong sense of "possession" - each line of software we write should be only ours. Ironically, I'm the only programmer (ATM), but we're planning in hiring others. Since my bosses wouldn't count the new programmers as people they can trust, they have an issue with the copies of the source code. We use Git, so they would have a entire copy of each of the projects they work on, when they clone the repository. We can restrict access to them to a single key with Gitolite and bind that to their PC's, but they can copy those keys to another computer and they would have the repository access in another PC. Also (and the most obvious method) they could just upload the files somewhere else, add another remote, or just copy the files to an USB drive. Is there any (perhaps clever) way to prevent events like these?

  Read the article

• optimization mvc code

  - by user276640

  i have such code var prj = _dataContext.Project.FirstOrDefault(p => p.isPopular == true); if (prj != null) { prj.isPopular = false; _dataContext.SaveChanges(); } prj = Details(id); prj.isPopular = true; _dataContext.SaveChanges(); idea-i have only one record with value true in field isPopular, so i get it and make false, then i get object by id and make it isPopular true. i don't like 2 calls on savechanges. any ideas?

  Read the article

• code optimization; switch versus if's

  - by KaiserJohaan

  Hello, I have a question about whether to use 'case' or 'ifs' in a function that gets called quite alot. Here's the following as it is now, in 'ifs'; the code is self-explanatory: int identifyMsg(char* textbuff) { if (!strcmp(textbuff,"text")) { return 1; } if (!strcmp(textbuff,"name")) { return 2; } if (!strcmp(textbuff,"list")) { return 3; } if (!strcmp(textbuff,"remv")) { return 4; } if (!strcmp(textbuff,"ipad")) { return 5; } if (!strcmp(textbuff,"iprm")) { return 6; } return 0; } My question is: Would a switch perform better? I know if using ifs, I can place the most likely options at the top.

  Read the article

• Code optimization - Unused methods

  - by Yochai Timmer

  How can I tell if a method will never be used ? I know that for dll files and libraries you can't really know if someone else (another project) will ever use the code. In general I assume that anything public might be used somewhere else. But what about private methods ? Is it safe to assume that if I don't see an explicit call to that method, it won't be used ? I assume that for private methods it's easier to decide. But is it safe to decide it ONLY for private methods ?

  Read the article

• Insert takes too long, code optimization needed

  - by Pentium10

  I have some code I use to transfer a table1 values to another table2, they are sitting in different database. It's slow when I have 100.000 records. It takes forever to finish, 10+ minutes. (Windows Mobile smartphone) What can I do? cmd.CommandText = "insert into " + TableName + " select * from sync2." + TableName+""; cmd.ExecuteNonQuery(); EDIT The problem is not resolved. I am still after answers.

  Read the article

< Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >