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• Is software support an option for your career?

  - by Maria Sandu

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 If you have a technical background, why should you choose a career in support? We have invited Serban to answer these questions and to give us an overview of one of the biggest technical teams in Oracle Romania. He’s been with Oracle for 7 years leading the local PeopleSoft Financials & Supply Chain Support team. Back in 2013 Serban started building a new support team in Romania – Fusion HCM. His current focus is building a strong support team for Fusion HCM, latest solution for Business HR Professionals from Oracle. The solution is offered both on Premise (customer site installation) but more important as a Cloud offering – SaaS.  So, why should a technical person choose Software Support over other technical areas?  “I think it is mainly because of the high level of technical skills required to provide the best technical solutions to our customers. Oracle Software Support covers complex solutions going from Database or Middleware to a vast area of business applications (basically covering any needs that a large enterprise may have). Working with such software requires very strong skills both technical and functional for the different areas, going from Finance, Supply Chain Management, Manufacturing, Sales to other very specific business processes. Our customers are large enterprises that already have a support layer inside their organization and therefore the Oracle Technical Support Engineers are working with highly specialized staff (DBA’s, System/Application Admins, Implementation Consultants). This is a very important aspect for our engineers because they need to be highly skilled to match our customer’s specialist’s expectations”.  What’s the career path in your team? “Technical Analysts joining our teams have a clear growth path. The main focus is to become a master of the product they will support. I think one need 1 or 2 years to reach a good level of understanding the product and delivering optimal solutions because of the complexity of our products. At a later stage, engineers can choose their professional development areas based on the business needs and preferences and then further grow towards as technical expert or a management role. We have analysts that have more than 15 years of technical expertise and they still learn and grow in technical area. Important fact is, due to the expansion of the Romanian Software support center, there are various management opportunities. So, if you want to leverage your experience and if you want to have people management responsibilities Oracle Software Support is the place to be!”  Our last question to Serban was about the benefits of being part of Oracle Software Support. Here is what he said: “We believe that Oracle delivers “State of the art” Support level to our customers. This is not possible without high investment in our staff. We commit from the start to support any technical analyst that joins us (being junior or very senior) with any training needs they have for their job. We have various technical trainings as well as soft-skills trainings required for a customer facing professional to be successful in his role. Last but not least, we’re aiming to make Oracle Romania SW Support a global center of excellence which means we’re investing a lot in our employees.”  If you’re looking for a job where you can combine your strong technical skills with customer interaction Oracle Software Support is the place to be! Send us your CV at [email protected]. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Database Partitioning and Multiple Data Source Considerations

  - by Jeffrey McDaniel

  With the release of P6 Reporting Database 3.0 partitioning was added as a feature to help with performance and data management.  Careful investigation of requirements should be conducting prior to installation to help improve overall performance throughout the lifecycle of the data warehouse, preventing future maintenance that would result in data loss. Before installation try to determine how many data sources and partitions will be required along with the ranges.  In P6 Reporting Database 3.0 any adjustments outside of defaults must be made in the scripts and changes will require new ETL runs for each data source.  Considerations: 1. Standard Edition or Enterprise Edition of Oracle Database.   If you aren't using Oracle Enterprise Edition Database; the partitioning feature is not available. Multiple Data sources are only supported on Enterprise Edition of Oracle   Database. 2. Number of Data source Ids for partitioning during configuration.   This setting will specify how many partitions will be allocated for tables containing data source information.  This setting requires some evaluation prior to installation as       there are repercussions if you don't estimate correctly.   For example, if you configured the software for only 2 data sources and the partition setting was set to 2, however along came a 3rd data source.  The necessary steps to  accommodate this change are as follows: a) By default, 3 partitions are configured in the Reporting Database scripts. Edit the create_star_tables_part.sql script located in <installation directory>\star\scripts   and search for partition.  You’ll see P1, P2, P3.  Add additional partitions and sub-partitions for P4 and so on. These will appear in several areas.  (See P6 Reporting Database 3.0 Installation and Configuration guide for more information on this and how to adjust partition ranges). b) Run starETL -r.  This will recreate each table with the new partition key.  The effect of this step is that all tables data will be lost except for history related tables.   c) Run starETL for each of the 3 data sources (with the data source # (starETL.bat "-s2" -as defined in P6 Reporting Database 3.0 Installation and Configuration guide) The best strategy for this setting is to overestimate based on possible growth.  If during implementation it is deemed that there are atleast 2 data sources with possibility for growth, it is a better idea to set this setting to 4 or 5, allowing room for the future and preventing a ‘start over’ scenario. 3. The Number of Partitions and the Number of Months per Partitions are not specific to multi-data source.  These settings work in accordance to a sub partition of larger tables with regard to time related data.  These settings are dataset specific for optimization.  The number of months per partition is self explanatory, optimally the smaller the partition, the better query performance so if the dataset has an extremely large number of spread/history records, a lower number of months is optimal.  Working in accordance with this setting is the number of partitions, this will determine how many "buckets" will be created per the number of months setting.  For example, if you kept the default for # of partitions of 3, and select 2 months for each partitions you would end up with: -1st partition, 2 months -2nd partition, 2 months -3rd partition, all the remaining records Therefore with records to this setting, it is important to analyze your source db spread ranges and history settings when determining the proper number of months per partition and number of partitions to optimize performance.  Also be aware the DBA will need to monitor when these partition ranges will fill up and when additional partitions will need to be added.  If you get to the final range partition and there are no additional range partitions all data will be included into the last partition. 

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• Trac vs. Redmine vs. JIRA vs. FogBugz for one-man shop?

  - by kizzx2

  Background I am a one-man freelancer looking for a project management software that can provide the following requirements. I have used Trac for about a year now. Tried Redmine and FogBugz on Demand for a couple of weeks. Never tried JIRA before. Basically, I'm looking for a piece of software that: Facilitates developer-client communication/collaboration Does time tracking Requirements Record time estimates/Time tracking Clients must be able to create/edit his own tickets/cases Clients must not see Developer created tickets/cases (internal) Affordable (price) with multiple clients Nice-to-haves Supports multiple projects in one installation Free eclipse integration (Mylyn) Easy time-tracking without using the Web UI (Trac's post commit hook or Redmine's commit message scanning) Clients can access the Wiki Export the data to standard formats My evaluation Trac can basically fulfill most of the above requirements, but with lots of customizations and plug-ins that it doesn't feel so clean. One downside is that the main trunk (0.11) has been around for a year or more and I still haven't seen much tendency of any upgrades coming up. Redmine has the cleanest Web UI. It's design philosophy seems to be the most elegant, with its innovative commit message scanning and stuff. However, the current version doesn't seem to be very mature and stable yet. It doesn't support internal (private) tickets and the time-tracking commit message patch doesn't support the trunk version. The good thing about it is that the main trunk still seems to be actively developed. FogBugz is actually a very well written piece of software. However the idea of paying $25/month for the client to be able to log-in to the system seems a little bit too far off for an individual developer. The free version supports letting clients create/view their own cases using email, which is a sub-optimal alternative to having a full-fledged list of the user's own cases. That also means clients can't read/write wiki pages. Its time-tracking approach is innovative and good though. However the fact that all the eclipse integration (Bugclipse, Foglyn) are commercial. Yet other investments before I can use my bug-tracker! If I revert back to the Web UI, it's not really a fast rendering Web service. Also, the in-built report functions are excellent (e.g. evidence based scheduling) JIRA is something I have zero experience with. Can someone with JIRA experience recommend why it might be a good fit for this particular situation? Question Can we share experience on this? Any specific plugins/customizations would that would best suit the requirements for this case?

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• Python - calculate multinomial probability density functions on large dataset?

  - by Seafoid

  Hi, I originally intended to use MATLAB to tackle this problem but the inbuilt functions has limitations that do not suit my goal. The same limitation occurs in NumPy. I have two tab-delimited files. The first is a file showing amino acid residue, frequency and count for an in-house database of protein structures, i.e. A 0.25 1 S 0.25 1 T 0.25 1 P 0.25 1 The second file consists of quadruplets of amino acids and the number of times they occur, i.e. ASTP 1 Note, there are 8,000 such quadruplets. Based on the background frequency of occurence of each amino acid and the count of quadruplets, I aim to calculate the multinomial probability density function for each quadruplet and subsequently use it as the expected value in a maximum likelihood calculation. The multinomial distribution is as follows: f(x|n, p) = n!/(x1!*x2!*...*xk!)*((p1^x1)*(p2^x2)*...*(pk^xk)) where x is the number of each of k outcomes in n trials with fixed probabilities p. n is 4 four in all cases in my calculation. I have created three functions to calculate this distribution. # functions for multinomial distribution def expected_quadruplets(x, y): expected = x*y return expected # calculates the probabilities of occurence raised to the number of occurrences def prod_prob(p1, a, p2, b, p3, c, p4, d): prob_prod = (pow(p1, a))*(pow(p2, b))*(pow(p3, c))*(pow(p4, d)) return prob_prod # factorial() and multinomial_coefficient() work in tandem to calculate C, the multinomial coefficient def factorial(n): if n <= 1: return 1 return n*factorial(n-1) def multinomial_coefficient(a, b, c, d): n = 24.0 multi_coeff = (n/(factorial(a) * factorial(b) * factorial(c) * factorial(d))) return multi_coeff The problem is how best to structure the data in order to tackle the calculation most efficiently, in a manner that I can read (you guys write some cryptic code :-)) and that will not create an overflow or runtime error. To data my data is represented as nested lists. amino_acids = [['A', '0.25', '1'], ['S', '0.25', '1'], ['T', '0.25', '1'], ['P', '0.25', '1']] quadruplets = [['ASTP', '1']] I initially intended calling these functions within a nested for loop but this resulted in runtime errors or overfloe errors. I know that I can reset the recursion limit but I would rather do this more elegantly. I had the following: for i in quadruplets: quad = i[0].split(' ') for j in amino_acids: for k in quadruplets: for v in k: if j[0] == v: multinomial_coefficient(int(j[2]), int(j[2]), int(j[2]), int(j[2])) I haven'te really gotten to how to incorporate the other functions yet. I think that my current nested list arrangement is sub optimal. I wish to compare the each letter within the string 'ASTP' with the first component of each sub list in amino_acids. Where a match exists, I wish to pass the appropriate numeric values to the functions using indices. Is their a better way? Can I append the appropriate numbers for each amino acid and quadruplet to a temporary data structure within a loop, pass this to the functions and clear it for the next iteration? Thanks, S :-)

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• Crawling engine architecture - Java/ Perl integration

  - by Bigtwinz

  Hi all, I am looking to develop a management and administration solution around our webcrawling perl scripts. Basically, right now our scripts are saved in SVN and are manually kicked off by SysAdmin/devs etc. Everytime we need to retrieve data from new sources we have to create a ticket with business instructions and goals. As you can imagine, not an optimal solution. There are 3 consistent themes with this system: the retrieval of data has a "conceptual structure" for lack of a better phrase i.e. the retrieval of information follows a particular path we are only looking for very specific information so we dont have to really worry about extensive crawling for awhile (think thousands-tens of thousands of pages vs millions) crawls are url-based instead of site-based. As I enhance this alpha version to a more production-level beta I am looking to add automation and management of the retrieval of data. Additionally our other systems are Java (which I'm more proficient in) and I'd like to compartmentalize the perl aspects so we dont have to lean heavily on outside help. I've evaluated the usual suspects Nutch, Droid etc but the time spent on modifying those frameworks to suit our specific information retrieval cant be justified. So I'd like your thoughts regarding the following architecture. I want to create a solution which use Java as the interface for managing and execution of the perl scripts use Java for configuration and data access stick with perl for retrieval An example use case would be a data analyst delivers us a requirement for crawling perl developer creates the required script and uses this webapp to submit the script (which gets saved to the filesystem) the script gets kicked off from the webapp with specific parameters .... Webapp should be able to create multiple threads of the perl script to initiate multiple crawlers. So questions are what do you think how solid is integration between Java and Perl specifically from calling perl from java has someone used such a system which actually is part perl repository The goal really is to not have a whole bunch of unorganized perl scripts and put some management and organization on our information retrieval. Also, I know I can use perl do do the web part of what we want - but as I mentioned before - trying to keep perl focused. But it seems assbackwards I'm not adverse to making it an all perl solution. Open to any all suggestions and opinions. Thanks

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• Another design-related C++ question

  - by Kotti

  Hi! I am trying to find some optimal solutions in C++ coding patterns, and this is one of my game engine - related questions. Take a look at the game object declaration (I removed almost everything, that has no connection with the question). // Abstract representation of a game object class Object : public Entity, IRenderable, ISerializable { // Object parameters // Other not really important stuff public: // @note Rendering template will never change while // the object 'lives' Object(RenderTemplate& render_template, /* params */) : /*...*/ { } private: // Object rendering template RenderTemplate render_template; public: /** * Default object render method * Draws rendering template data at (X, Y) with (Width, Height) dimensions * * @note If no appropriate rendering method overload is specified * for any derived class, this method is called * * @param Backend & b * @return void * @see */ virtual void Render(Backend& backend) const { // Render sprite from object's // rendering template structure backend.RenderFromTemplate( render_template, x, y, width, height ); } }; Here is also the IRenderable interface declaration: // Objects that can be rendered interface IRenderable { /** * Abstract method to render current object * * @param Backend & b * @return void * @see */ virtual void Render(Backend& b) const = 0; } and a sample of a real object that is derived from Object (with severe simplifications :) // Ball object class Ball : public Object { // Ball params public: virtual void Render(Backend& b) const { b.RenderEllipse(/*params*/); } }; What I wanted to get is the ability to have some sort of standard function, that would draw sprite for an object (this is Object::Render) if there is no appropriate overload. So, one can have objects without Render(...) method, and if you try to render them, this default sprite-rendering stuff is invoked. And, one can have specialized objects, that define their own way of being rendered. I think, this way of doing things is quite good, but what I can't figure out - is there any way to split the objects' "normal" methods (like Resize(...) or Rotate(...)) implementation from their rendering implementation? Because if everything is done the way described earlier, a common .cpp file, that implements any type of object would generally mix the Resize(...), etc methods implementation and this virtual Render(...) method and this seems to be a mess. I actually want to have rendering procedures for the objects in one place and their "logic implementation" - in another. Is there a way this can be done (maybe alternative pattern or trick or hint) or this is where all this polymorphic and virtual stuff sucks in terms of code placement?

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• Lawler's Algorithm Implementation Assistance

  - by Richard Knop

  Here is my implemenation of Lawler's algorithm in PHP (I know... but I'm used to it): <?php $jobs = array(1, 2, 3, 4, 5, 6); $jobsSubset = array(2, 5, 6); $n = count($jobs); $processingTimes = array(2, 3, 4, 3, 2, 1); $dueDates = array(3, 15, 9, 7, 11, 20); $optimalSchedule = array(); foreach ($jobs as $j) { $optimalSchedule[] = 0; } $dicreasedCardinality = array(); for ($i = $n; $i >= 1; $i--) { $x = 0; $max = 0; // loop through all jobs for ($j = 0; $j < $i; $j++) { // ignore if $j already is in the $dicreasedCardinality array if (false === in_array($j, $dicreasedCardinality)) { // if the job has no succesor in $jobsSubset if (false === isset($jobs[$j+1]) || false === in_array($jobs[$j+1], $jobsSubset)) { // here I find an array index of a job with the maximum due date // amongst jobs with no sucessor in $jobsSubset if ($x < $dueDates[$j]) { $x = $dueDates[$j]; $max = $j; } } } } // move the job at the end of $optimalSchedule $optimalSchedule[$i-1] = $jobs[$max]; // decrease the cardinality of $jobs $dicreasedCardinality[] = $max; } print_r($optimalSchedule); Now the above returns an optimal schedule like this: Array ( [0] => 1 [1] => 1 [2] => 1 [3] => 3 [4] => 2 [5] => 6 ) Which doesn't seem right to me. The problem might be with my implementation of the algorithm because I am not sure I understand it correctly. I used this source to implement it: http://www.google.com/books?id=aSiBs6PDm9AC&pg=PA166&dq=lawler%27s+algorithm+code&lr=&hl=sk&cd=4#v=onepage&q=&f=false The description there is a little confusing. For example, I didn't quite get how is the subset D defined (I guess it is arbitrary). Could anyone help me out with this? I have been trying to find some sources with simpler explanation of the algorithm but all sources I found were even more complicated (with math proofs and such) so I am stuck with the link above. Yes, this is a homework, if it wasn't obvious. I still have few weeks to crack this but I have spent few days already trying to get how exactly this algorithm works with no success so I don't think I will get any brighter during that time.

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• Java web-app debugging not possible due to direct undeploy on debug

  - by Hendrik

  When i try to debug my webapp it starts up the tomcat server and the application, but shuts down the debugger shortly before the app gets usable. I see the debugging toolbar for a second before it vanishes again, though the app keeps running. Tomcat-log: Listening for transport dt_socket at address: 11555 23.03.2010 01:24:35 org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: .:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java 23.03.2010 01:24:35 org.apache.coyote.http11.Http11Protocol init INFO: Initializing Coyote HTTP/1.1 on http-8084 23.03.2010 01:24:35 org.apache.catalina.startup.Catalina load INFO: Initialization processed in 847 ms 23.03.2010 01:24:35 org.apache.catalina.core.StandardService start INFO: Starting service Catalina 23.03.2010 01:24:35 org.apache.catalina.core.StandardEngine start INFO: Starting Servlet Engine: Apache Tomcat/6.0.20 log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader). log4j:WARN Please initialize the log4j system properly. 23.03.2010 01:24:41 org.apache.coyote.http11.Http11Protocol start INFO: Starting Coyote HTTP/1.1 on http-8084 23.03.2010 01:24:41 org.apache.jk.common.ChannelSocket init INFO: JK: ajp13 listening on /0.0.0.0:8009 23.03.2010 01:24:41 org.apache.jk.server.JkMain start INFO: Jk running ID=0 time=0/78 config=null 23.03.2010 01:24:41 org.apache.catalina.startup.Catalina start INFO: Server startup in 5855 ms 23.03.2010 01:24:42 org.apache.catalina.startup.HostConfig checkResources INFO: Undeploying context [] 23.03.2010 01:24:45 org.apache.catalina.core.StandardContext start INFO: Container org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/] has already been started Debugging log: Attached JPDA debugger to localhost:11555 Checking data source definitions for missing JDBC drivers... Deploying JDBC driver to /Applications/NetBeans/apache-tomcat-6.0.20/lib/mysql-connector-java-5.1.6-bin.jar Stopping Tomcat process... Waiting for Tomcat... Tomcat server stopped. Starting Tomcat process... Waiting for Tomcat... Tomcat server started. Undeploying ... OK - Undeployed application at context path / In-place deployment at /path/to/project/dir/build/web deploy?config=file%3A%2Fvar%2Ffolders%2FZP%2FZPbqxGrbHFaUlXzAfgWV1%2B%2B%2B%2BTQ%2F-Tmp-%2Fcontext734173871283203218.xml&path=/ OK - Deployed application at context path / start?path=/ Start is in progress... OK - Started application at context path / debug-display-browser: Browsing: http://localhost:8084/ connect-client-debugger: BUILD SUCCESSFUL (total time: 18 seconds) System is Netbeans 6.8 on MacOS 10.6.2. Thank you very much, guys!

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• Finding minimum cut-sets between bounded subgraphs

  - by Tore

  If a game map is partitioned into subgraphs, how to minimize edges between subgraphs? I have a problem, Im trying to make A* searches through a grid based game like pacman or sokoban, but i need to find "enclosures". What do i mean by enclosures? subgraphs with as few cut edges as possible given a maximum size and minimum size for number of vertices for each subgraph that act as a soft constraints. Alternatively you could say i am looking to find bridges between subgraphs, but its generally the same problem. Given a game that looks like this, what i want to do is find enclosures so that i can properly find entrances to them and thus get a good heuristic for reaching vertices inside these enclosures. So what i want is to find these colored regions on any given map. My Motivation The reason for me bothering to do this and not just staying content with the performance of a simple manhattan distance heuristic is that an enclosure heuristic can give more optimal results and i would not have to actually do the A* to get some proper distance calculations and also for later adding competitive blocking of opponents within these enclosures when playing sokoban type games. Also the enclosure heuristic can be used for a minimax approach to finding goal vertices more properly. A possible solution to the problem is the Kernighan-Lin algorithm: function Kernighan-Lin(G(V,E)): determine a balanced initial partition of the nodes into sets A and B do A1 := A; B1 := B compute D values for all a in A1 and b in B1 for (i := 1 to |V|/2) find a[i] from A1 and b[i] from B1, such that g[i] = D[a[i]] + D[b[i]] - 2*c[a][b] is maximal move a[i] to B1 and b[i] to A1 remove a[i] and b[i] from further consideration in this pass update D values for the elements of A1 = A1 / a[i] and B1 = B1 / b[i] end for find k which maximizes g_max, the sum of g[1],...,g[k] if (g_max > 0) then Exchange a[1],a[2],...,a[k] with b[1],b[2],...,b[k] until (g_max <= 0) return G(V,E) My problem with this algorithm is its runtime at O(n^2 * lg(n)), i am thinking of limiting the nodes in A1 and B1 to the border of each subgraph to reduce the amount of work done. I also dont understand the c[a][b] cost in the algorithm, if a and b do not have an edge between them is the cost assumed to be 0 or infinity, or should i create an edge based on some heuristic. Do you know what c[a][b] is supposed to be when there is no edge between a and b? Do you think my problem is suitable to use a multi level problem? Why or why not? Do you have a good idea for how to reduce the work done with the kernighan-lin algorithm for my problem?

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• ISQLQuery using AddJoin not loading related instance

  - by Remi Despres-Smyth

  I've got a problem using an ISQLQuery with an AddJoin. The entity I'm trying to return is RegionalFees, which has a composite-id which includes a Province instance. (This is the the instance being improperly loaded.) Here's the mapping: <class name="Project.RegionalFees, Project" table="tblRegionalFees"> <composite-id name="Id" class="Project.RegionalFeesId, project" unsaved-value="any" access="property"> <key-many-to-one class="Project.Province, Project" name="Region" access="property" column="provinceId" not-found="exception" /> <key-property name="StartDate" access="property" column="startDate" type="DateTime" /> </composite-id> <property name="SomeFee" column="someFee" type="Decimal" /> <property name="SomeOtherFee" column="someOtherFee" type="Decimal" /> <!-- Other unrelated stuff --> </class> <class name="Project.Province, Project" table="trefProvince" mutable="false"> <id name="Id" column="provinceId" type="Int64" unsaved-value="0"> <generator class="identity" /> </id> <property name="Code" column="code" access="nosetter.pascalcase-m-underscore" /> <property name="Label" column="label" access="nosetter.pascalcase-m-underscore" /> </class> Here's my query method: public IEnumerable<RegionalFees> GetRegionalFees() { // Using an ISQLQuery cause there doesn't appear to be an equivalent of // the SQL HAVING clause, which would be optimal for loading this set const String qryStr = "SELECT * " + "FROM tblRegionalFees INNER JOIN trefProvince " + "ON tblRegionalFees.provinceId=trefProvince.provinceId " + "WHERE EXISTS ( " + "SELECT provinceId, MAX(startDate) AS MostRecentFeesDate " + "FROM tblRegionalFees InnerRF " + "WHERE tblRegionalFees.provinceId=InnerRF.provinceId " + "AND startDate <= ? " + "GROUP BY provinceId " + "HAVING tblRegionalFees.startDate=MAX(startDate))"; var qry = NHibernateSessionManager.Instance.GetSession().CreateSQLQuery(qryStr); qry.SetDateTime(0, DateTime.Now); qry.AddEntity("RegFees", typeof(RegionalFees)); qry.AddJoin("Region", "RegFees.Id.Region"); return qry.List<RegionalFees>(); } The odd behavior here is that when I call GetRegionalFees (whose goal is to load just the most recent fee instances per region), it all loads fine if the Province instance is a proxy. If, however, Province is not loaded as a transparent proxy, the Province instance which is part of RegionalFees' RegionalFeesId property has null Code and Region values, although the Id value is set correctly. It looks to me like I have a problem in how I'm joining the Province class - since if it's lazy loaded the id is set from tblRegionalFees, and it gets loaded independently afterwards - but I haven't been able to figure out the solution.

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• Data denormalization and C# objects DB serialization

  - by Robert Koritnik

  I'm using a DB table with various different entities. This means that I can't have an arbitrary number of fields in it to save all kinds of different entities. I want instead save just the most important fields (dates, reference IDs - kind of foreign key to various other tables, most important text fields etc.) and an additional text field where I'd like to store more complete object data. the most obvious solution would be to use XML strings and store those. The second most obvious choice would be JSON, that usually shorter and probably also faster to serialize/deserialize... And is probably also faster. But is it really? My objects also wouldn't need to be strictly serializable, because JsonSerializer is usually able to serialize anything. Even anonymous objects, that may as well be used here. What would be the most optimal solution to solve this problem? Additional info My DB is highly normalised and I'm using Entity Framework, but for the purpose of having external super-fast fulltext search functionality I'm sacrificing a bit DB denormalisation. Just for the info I'm using SphinxSE on top of MySql. Sphinx would return row IDs that I would use to fast query my index optimised conglomerate table to get most important data from it much much faster than querying multiple tables all over my DB. My table would have columns like: RowID (auto increment) EntityID (of the actual entity - but not directly related because this would have to point to different tables) EntityType (so I would be able to get the actual entity if needed) DateAdded (record timestamp when it's been added into this table) Title Metadata (serialized data related to particular entity type) This table would be indexed with SPHINX indexer. When I would search for data using this indexer I would provide a series of EntityIDs and a limit date. Indexer would have to return a very limited paged amount of RowIDs ordered by DateAdded (descending). I would then just join these RowIDs to my table and get relevant results. So this won't actually be full text search but a filtering search. Getting RowIDs would be very fast this way and getting results back from the table would be much faster than comparing EntityIDs and DateAdded comparisons even though they would be properly indexed.

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• Succinct introduction to C++/CLI for C#/Haskell/F#/JS/C++/... programmer

  - by Henrik

  Hello everybody, I'm trying to write integrations with the operating system and with things like active directory and Ocropus. I know a bunch of programming languages, including those listed in the title. I'm trying to learn exactly how C++/CLI works, but can't find succinct, exact and accurate descriptions online from the searching that I have done. So I ask here. Could you tell me the pitfalls and features of C++/CLI? Assume I know all of C# and start from there. I'm not an expert in C++, so some of my questions' answers might be "just like C++", but could say that I am at C#. I would like to know things like: Converting C++ pointers to CLI pointers, Any differences in passing by value/doubly indirect pointers/CLI pointers from C#/C++ and what is 'recommended'. How do gcnew, __gc, __nogc work with Polymorphism Structs Inner classes Interfaces The "fixed" keyword; does that exist? Compiling DLLs loaded into the kernel with C++/CLI possible? Loaded as device drivers? Invoked by the kernel? What does this mean anyway (i.e. to load something into the kernel exactly; how do I know if it is?)? L"my string" versus "my string"? wchar_t? How many types of chars are there? Are we safe in treating chars as uint32s or what should one treat them as to guarantee language indifference in code? Finalizers (~ClassName() {}) are discouraged in C# because there are no garantuees they will run deterministically, but since in C++ I have to use "delete" or use copy-c'tors as to stack allocate memory, what are the recommendations between C#/C++ interactions? What are the pitfalls when using reflection in C++/CLI? How well does C++/CLI work with the IDisposable pattern and with SafeHandle, SafeHandleZeroOrMinusOneIsInvalid? I've read briefly about asynchronous exceptions when doing DMA-operations, what are these? Are there limitations you impose upon yourself when using C++ with CLI integration rather than just doing plain C++? Attributes in C++ similar to Attributes in C#? Can I use the full meta-programming patterns available in C++ through templates now and still have it compile like ordinary C++? Have you tried writing C++/CLI with boost? What are the optimal ways of interfacing the boost library with C++/CLI; can you give me an example of passing a lambda expression to an iterator/foldr function? What is the preferred way of exception handling? Can C++/CLI catch managed exceptions now? How well does dynamic IL generation work with C++/CLI? Does it run on Mono? Any other things I ought to know about?

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• Succinct introduction to C++/CLI for C#/Haskell/F#/JS/C++/... programmer

  - by Henrik

  Hello everybody, I'm trying to write integrations with the operating system and with things like active directory and Ocropus. I know a bunch of programming languages, including those listed in the title. I'm trying to learn exactly how C++/CLI works, but can't find succinct, exact and accurate descriptions online from the searching that I have done. So I ask here. Could you tell me the pitfalls and features of C++/CLI? Assume I know all of C# and start from there. I'm not an expert in C++, so some of my questions' answers might be "just like C++", but could say that I am at C#. I would like to know things like: Converting C++ pointers to CLI pointers, Any differences in passing by value/doubly indirect pointers/CLI pointers from C#/C++ and what is 'recommended'. How do gcnew, __gc, __nogc work with Polymorphism Structs Inner classes Interfaces The "fixed" keyword; does that exist? Compiling DLLs loaded into the kernel with C++/CLI possible? Loaded as device drivers? Invoked by the kernel? What does this mean anyway (i.e. to load something into the kernel exactly; how do I know if it is?)? L"my string" versus "my string"? wchar_t? How many types of chars are there? Are we safe in treating chars as uint32s or what should one treat them as to guarantee language indifference in code? Finalizers (~ClassName() {}) are discouraged in C# because there are no garantuees they will run deterministically, but since in C++ I have to use "delete" or use copy-c'tors as to stack allocate memory, what are the recommendations between C#/C++ interactions? What are the pitfalls when using reflection in C++/CLI? How well does C++/CLI work with the IDisposable pattern and with SafeHandle, SafeHandleZeroOrMinusOneIsInvalid? I've read briefly about asynchronous exceptions when doing DMA-operations, what are these? Are there limitations you impose upon yourself when using C++ with CLI integration rather than just doing plain C++? Attributes in C++ similar to Attributes in C#? Can I use the full meta-programming patterns available in C++ through templates now and still have it compile like ordinary C++? Have you tried writing C++/CLI with boost? What are the optimal ways of interfacing the boost library with C++/CLI; can you give me an example of passing a lambda expression to an iterator/foldr function? What is the preferred way of exception handling? Can C++/CLI catch managed exceptions now? How well does dynamic IL generation work with C++/CLI? Does it run on Mono? Any other things I ought to know about?

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• Java Nimbus LAF with transparent text fields

  - by Software Monkey

  I have an application that uses disabled JTextFields in several places which are intended to be transparent - allowing the background to show through instead of the text field's normal background. When running the new Nimbus LAF these fields are opaque (despite setting setOpaque(false)), and my UI is broken. It's as if the LAF is ignoring the opaque property. Setting a background color explicitly is both difficult in several places, and less than optimal due to background images actually doesn't work - it still paints it's LAF default background over the top, leaving a border-like appearance (the splash screen below has the background explicitly set to match the image). Any ideas on how I can get Nimbus to not paint the background for a JTextField? Note: I need a JTextField, rather than a JLabel, because I need the thread-safe setText(), and wrapping capability. Note: My fallback position is to continue using the system LAF, but Nimbus does look substantially better. See example images below. Conclusions The surprise at this behavior is due to a misinterpretation of what setOpaque() is meant to do - from the Nimbus bug report: This is a problem the the orginal design of Swing and how it has been confusing for years. The issue is setOpaque(false) has had a side effect in exiting LAFs which is that of hiding the background which is not really what it is ment for. It is ment to say that the component my have transparent parts and swing should paint the parent component behind it. It's unfortunate that the Nimbus components also appear not to honor setBackground(null) which would otherwise be the recommended way to stop the background painting. Setting a fully transparent background seems unintuitive to me. In my opinion, setOpaque()/isOpaque() is a faulty public API choice which should have been only: public boolean isFullyOpaque(); I say this, because isOpaque()==true is a contract with Swing that the component subclass will take responsibility for painting it's entire background - which means the parent can skip painting that region if it wants (which is an important performance enhancement). Something external cannot directly change this contract (legitimately), whose fulfillment may be coded into the component. So the opacity of the component should not have been settable using setOpaque(). Instead something like setBackground(null) should cause many components to "no long have a background" and therefore become not fully opaque. By way of example, in an ideal world most components should have an isOpaque() that looks like this: public boolean isOpaque() { return (background!=null); }

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• How to make efficient code emerge through unit testing

  - by Jean

  Hi, I participate in a TDD Coding Dojo, where we try to practice pure TDD on simple problems. It occured to me however that the code which emerges from the unit tests isn't the most efficient. Now this is fine most of the time, but what if the code usage grows so that efficiency becomes a problem. I love the way the code emerges from unit testing, but is it possible to make the efficiency property emerge through further tests ? Here is a trivial example in ruby: prime factorization. I followed a pure TDD approach making the tests pass one after the other validating my original acceptance test (commented at the bottom). What further steps could I take, if I wanted to make one of the generic prime factorization algorithms emerge ? To reduce the problem domain, let's say I want to get a quadratic sieve implementation ... Now in this precise case I know the "optimal algorithm, but in most cases, the client will simply add a requirement that the feature runs in less than "x" time for a given environment. require 'shoulda' require 'lib/prime' class MathTest < Test::Unit::TestCase context "The math module" do should "have a method to get primes" do assert Math.respond_to? 'primes' end end context "The primes method of Math" do should "return [] for 0" do assert_equal [], Math.primes(0) end should "return [1] for 1 " do assert_equal [1], Math.primes(1) end should "return [1,2] for 2" do assert_equal [1,2], Math.primes(2) end should "return [1,3] for 3" do assert_equal [1,3], Math.primes(3) end should "return [1,2] for 4" do assert_equal [1,2,2], Math.primes(4) end should "return [1,5] for 5" do assert_equal [1,5], Math.primes(5) end should "return [1,2,3] for 6" do assert_equal [1,2,3], Math.primes(6) end should "return [1,3] for 9" do assert_equal [1,3,3], Math.primes(9) end should "return [1,2,5] for 10" do assert_equal [1,2,5], Math.primes(10) end end # context "Functionnal Acceptance test 1" do # context "the prime factors of 14101980 are 1,2,2,3,5,61,3853"do # should "return [1,2,3,5,61,3853] for ${14101980*14101980}" do # assert_equal [1,2,2,3,5,61,3853], Math.primes(14101980*14101980) # end # end # end end and the naive algorithm I created by this approach module Math def self.primes(n) if n==0 return [] else primes=[1] for i in 2..n do if n%i==0 while(n%i==0) primes<<i n=n/i end end end primes end end end

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• Converting to async,await using async targeting package

  - by e4rthdog

  I have this: private void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; var task = Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); task.ContinueWith(t => { btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = t.Result.Description; lblItemCodeValue.Text = t.Result.Code; lblQuantityValue.Text = t.Result.AvailableQuantity.ToString(); },TaskScheduler .FromCurrentSynchronizationContext() ); LotFocus(true); } and i followed J. Skeet's advice to move into async,await in my .NET 4.0 app. I converted into this: private async void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; JDEItemLotAvailability itm = await Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = itm.Description; lblItemCodeValue.Text = itm.Code; lblQuantityValue.Text = itm.AvailableQuantity.ToString(); LotFocus(true); } It works fine. What confuses me is that i could do it without using Task but just the method of my Dal. But that means that i must have modified my Dal method, which is something i dont want? I would appreciate if someone would explain to me in "plain" words if what i did is optimal or not and why. Thanks P.s. My dal method public bool CheckLotExistF41021(string _lot, string _mcu, string _locn) { using (OleDbConnection con = new OleDbConnection(this.conString)) { OleDbCommand cmd = new OleDbCommand(); cmd.CommandText = "select lilotn from proddta.f41021 " + "where lilotn = ? and trim(limcu) = ? and lilocn= ?"; cmd.Parameters.AddWithValue("@lotn", _lot); cmd.Parameters.AddWithValue("@mcu", _mcu); cmd.Parameters.AddWithValue("@locn", _locn); cmd.Connection = con; con.Open(); OleDbDataReader rdr = cmd.ExecuteReader(); bool _retval = rdr.HasRows; rdr.Close(); con.Close(); return _retval; } }

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• Non-linear regression models in PostgreSQL using R

  - by Dave Jarvis

  Background I have climate data (temperature, precipitation, snow depth) for all of Canada between 1900 and 2009. I have written a basic website and the simplest page allows users to choose category and city. They then get back a very simple report (without the parameters and calculations section): The primary purpose of the web application is to provide a simple user interface so that the general public can explore the data in meaningful ways. (A list of numbers is not meaningful to the general public, nor is a website that provides too many inputs.) The secondary purpose of the application is to provide climatologists and other scientists with deeper ways to view the data. (Using too many inputs, of course.) Tool Set The database is PostgreSQL with R (mostly) installed. The reports are written using iReport and generated using JasperReports. Poor Model Choice Currently, a linear regression model is applied against annual averages of daily data. The linear regression model is calculated within a PostgreSQL function as follows: SELECT regr_slope( amount, year_taken ), regr_intercept( amount, year_taken ), corr( amount, year_taken ) FROM temp_regression INTO STRICT slope, intercept, correlation; The results are returned to JasperReports using: SELECT year_taken, amount, year_taken * slope + intercept, slope, intercept, correlation, total_measurements INTO result; JasperReports calls into PostgreSQL using the following parameterized analysis function: SELECT year_taken, amount, measurements, regression_line, slope, intercept, correlation, total_measurements, execute_time FROM climate.analysis( $P{CityId}, $P{Elevation1}, $P{Elevation2}, $P{Radius}, $P{CategoryId}, $P{Year1}, $P{Year2} ) ORDER BY year_taken This is not an optimal solution because it gives the false impression that the climate is changing at a slow, but steady rate. Questions Using functions that take two parameters (e.g., year [X] and amount [Y]), such as PostgreSQL's regr_slope: What is a better regression model to apply? What CPAN-R packages provide such models? (Installable, ideally, using apt-get.) How can the R functions be called within a PostgreSQL function? If no such functions exist: What parameters should I try to obtain for functions that will produce the desired fit? How would you recommend showing the best fit curve? Keep in mind that this is a web app for use by the general public. If the only way to analyse the data is from an R shell, then the purpose has been defeated. (I know this is not the case for most R functions I have looked at so far.) Thank you!

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• java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.FilterDispatcher

  - by user714698

  log when start the tomcat Apr 28, 2011 10:52:57 AM org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: D:\software\jdk1.5.0_06\bin;.;C:\WINDOWS\system32;C:\WINDOWS;D:/software/jdk1.5.0_06/bin/../jre/bin/client;D:/software/jdk1.5.0_06/bin/../jre/bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\TortoiseSVN\bin.;D:\software\jdk1.5.0_06\bin;D:\software\Ant 1.7\bin;D:\software\Axis2-1.5.4\axis2-1.5.4-bin\axis2-1.5.4\bin;C:\Program Files\IDM Computer Solutions\UltraEdit\ Apr 28, 2011 10:52:58 AM org.apache.tomcat.util.digester.SetPropertiesRule begin WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:StrutsHelloWorld' did not find a matching property. Apr 28, 2011 10:52:58 AM org.apache.tomcat.util.digester.SetPropertiesRule begin WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:StrutsHelloWorld1' did not find a matching property. Apr 28, 2011 10:53:00 AM org.apache.coyote.http11.Http11Protocol init INFO: Initializing Coyote HTTP/1.1 on http-8080 Apr 28, 2011 10:53:00 AM org.apache.catalina.startup.Catalina load INFO: Initialization processed in 3657 ms Apr 28, 2011 10:53:00 AM org.apache.catalina.core.StandardService start INFO: Starting service Catalina Apr 28, 2011 10:53:00 AM org.apache.catalina.core.StandardEngine start INFO: Starting Servlet Engine: Apache Tomcat/6.0.32 Apr 28, 2011 10:53:01 AM org.apache.catalina.core.StandardContext filterStart SEVERE: Exception starting filter struts2 java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.FilterDispatcher at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:269) at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422) at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115) at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4071) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4725) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardHost.start(StandardHost.java:840) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463) at org.apache.catalina.core.StandardService.start(StandardService.java:525) at org.apache.catalina.core.StandardServer.start(StandardServer.java:754) at org.apache.catalina.startup.Catalina.start(Catalina.java:595) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) Apr 28, 2011 10:53:01 AM org.apache.catalina.core.StandardContext start SEVERE: Error filterStart Apr 28, 2011 10:53:01 AM org.apache.catalina.core.StandardContext start SEVERE: Context [/StrutsHelloWorld1] startup failed due to previous errors log4j:WARN No appenders could be found for logger (com.opensymphony.xwork2.config.providers.XmlConfigurationProvider). log4j:WARN Please initialize the log4j system properly. Apr 28, 2011 10:53:05 AM org.apache.coyote.http11.Http11Protocol start INFO: Starting Coyote HTTP/1.1 on http-8080 Apr 28, 2011 10:53:05 AM org.apache.jk.common.ChannelSocket init INFO: JK: ajp13 listening on /0.0.0.0:8009 Apr 28, 2011 10:53:05 AM org.apache.jk.server.JkMain start INFO: Jk running ID=0 time=0/46 config=null Apr 28, 2011 10:53:05 AM org.apache.catalina.startup.Catalina start INFO: Server startup in 4951 ms

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• Rush Hour - Solving the game

  - by Rubys

  Rush Hour if you're not familiar with it, the game consists of a collection of cars of varying sizes, set either horizontally or vertically, on a NxM grid that has a single exit. Each car can move forward/backward in the directions it's set in, as long as another car is not blocking it. You can never change the direction of a car. There is one special car, usually it's the red one. It's set in the same row that the exit is in, and the objective of the game is to find a series of moves (a move - moving a car N steps back or forward) that will allow the red car to drive out of the maze. I've been trying to think how to solve this problem computationally, and I can really not think of any good solution. I came up with a few: Backtracking. This is pretty simple - Recursion and some more recursion until you find the answer. However, each car can be moved a few different ways, and in each game state a few cars can be moved, and the resulting game tree will be HUGE. Some sort of constraint algorithm that will take into account what needs to be moved, and work recursively somehow. This is a very rough idea, but it is an idea. Graphs? Model the game states as a graph and apply some sort of variation on a coloring algorithm, to resolve dependencies? Again, this is a very rough idea. A friend suggested genetic algorithms. This is sort of possible but not easily. I can't think of a good way to make an evaluation function, and without that we've got nothing. So the question is - How to create a program that takes a grid and the vehicle layout, and outputs a series of steps needed to get the red car out? Sub-issues: Finding some solution. Finding an optimal solution (minimal number of moves) Evaluating how good a current state is Example: How can you move the cars in this setting, so that the red car can "exit" the maze through the exit on the right?

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• Java Hardware Acceleration

  - by Freezerburn

  I have been spending some time looking into the hardware acceleration features of Java, and I am still a bit confused as none of the sites that I found online directly and clearly answered some of the questions I have. So here are the questions I have for hardware acceleration in Java: 1) In Eclipse version 3.6.0, with the most recent Java update for Mac OS X (1.6u10 I think), is hardware acceleration enabled by default? I read somewhere that someCanvas.getGraphicsConfiguration().getBufferCapabilities().isPageFlipping() is supposed to give an indication of whether or not hardware acceleration is enabled, and my program reports back true when that is run on my main Canvas instance for drawing to. If my hardware acceleration is not enabled now, or by default, what would I have to do to enable it? 2) I have seen a couple articles here and there about the difference between a BufferedImage and VolatileImage, mainly saying that VolatileImage is the hardware accelerated image and is stored in VRAM for fast copy-from operations. However, I have also found some instances where BufferedImage is said to be hardware accelerated as well. Is BufferedImage hardware accelerated as well in my environment? What would be the advantage of using a VolatileImage if both types are hardware accelerated? My main assumption for the advantage of having a VolatileImage in the case of both having acceleration is that VolatileImage is able to detect when its VRAM has been dumped. But if BufferedImage also support acceleration now, would it not have the same kind of detection built into it as well, just hidden from the user, in case that the memory is dumped? 3) Is there any advantage to using someGraphicsConfiguration.getCompatibleImage/getCompatibleVolatileImage() as opposed to ImageIO.read() In a tutorial I have been reading for some general concepts about setting up the rendering window properly (tutorial) it uses the getCompatibleImage method, which I believe returns a BufferedImage, to get their "hardware accelerated" images for fast drawing, which ties into question 2 about if it is hardware accelerated. 4) This is less hardware acceleration, but it is something I have been curious about: do I need to order which graphics get drawn? I know that when using OpenGL via C/C++ it is best to make sure that the same graphic is drawn in all the locations it needs to be drawn at once to reduce the number of times the current texture needs to be switch. From what I have read, it seems as if Java will take care of this for me and make sure things are drawn in the most optimal fashion, but again, nothing has ever said anything like this clearly. 5) What AWT/Swing classes support hardware acceleration, and which ones should be used? I am currently using a class that extends JFrame to create a window, and adding a Canvas to it from which I create a BufferStrategy. Is this good practice, or is there some other type of way I should be implementing this? Thank you very much for your time, and I hope I provided clear questions and enough information for you to answer my several questions.

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• C Programming - My program is good enough for my assignment but I know its not good

  - by Joe

  Hi there I'm just starting an assignment for uni and it's raised a question for me. I don't understand how to return a string from a function without having a memory leak. char* trim(char* line) { int start = 0; int end = strlen(line) - 1; /* find the start position of the string */ while(isspace(line[start]) != 0) { start++; } //printf("start is %d\n", start); /* find the position end of the string */ while(isspace(line[end]) != 0) { end--; } //printf("end is %d\n", end); /* calculate string length and add 1 for the sentinel */ int len = end - start + 2; /* initialise char array to len and read in characters */ int i; char* trimmed = calloc(sizeof(char), len); for(i = 0; i < (len - 1); i++) { trimmed[i] = line[start + i]; } trimmed[len - 1] = '\0'; return trimmed; } as you can see I am returning a pointer to char which is an array. I found that if I tried to make the 'trimmed' array by something like: char trimmed[len]; then the compiler would throw up a message saying that a constant was expected on this line. I assume this meant that for some reason you can't use variables as the array length when initialising an array, although something tells me that can't be right. So instead I made my array by allocating some memory to a char pointer. I understand that this function is probably waaaaay sub-optimal for what it is trying to do, but what I really want to know is: 1. Can you normally initialise an array using a variable to declare the length like: char trimmed[len]; ? 2. If I had an array that was of that type (char trimmed[]) would it have the same return type as a pointer to char (ie char*). 3. If I make my array by callocing some memory and allocating it to a char pointer, how do I free this memory. It seems to me that once I have returned this array, I can't access it to free it as it is a local variable. Many thanks in advance Joe

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• iPhone: Speeding up a search that's polling 17,000 Core Data objects

  - by randombits

  I have a class that conforms to UISearchDisplayDelegate and contains a UISearchBar. This view is responsible for allowing the user to poll a store of about 17,000 objects that are currently managed by Core Data. Everytime the user types in a character, I created an instance of a SearchOperation (subclasses NSOperation) that queries Core Data to find results that might match the search. The code in the search controller looks something like: - (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope { // Update the filtered array based on the search text and scope in a secondary thread if ([searchText length] < 3) { [filteredList removeAllObjects]; // First clear the filtered array. [self setFilteredList:NULL]; [self.tableView reloadData]; return; } NSDictionary *searchdict = [NSDictionary dictionaryWithObjectsAndKeys:scope, @"scope", searchText, @"searchText", nil]; [aSearchQueue cancelAllOperations]; SearchOperation *searchOp = [[SearchOperation alloc] initWithDelegate:self dataDict:searchdict]; [aSearchQueue addOperation:searchOp]; } And my search is rather straight forward. SearchOperation is a subclass of NSOperation. I overwrote the main method with the following code: - (void)main { if ([self isCancelled]) { return; } NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext]; NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; [fetchRequest setEntity:entity]; NSPredicate *predicate = NULL; predicate = [NSPredicate predicateWithFormat:@"(someattr contains[cd] %@)", searchText]; [fetchRequest setPredicate:predicate]; NSError *error = NULL; NSArray *fetchResults = [managedObjectContext executeFetchRequest:fetchRequest error:&error]; [fetchRequest release]; if (self.delegate != nil) [self.delegate didFinishSearching:fetchResults]; [pool drain]; } This code works, but it has several issues. It's slow. Even though I have the search happening in a separate thread other than the UI thread, querying 17,000 objects is clearly not optimal. If I'm not careful, crashes can happen. I set the max concurrent searches in my NSOperationQueue to 1 to avoid this. What else can I do to make this search faster? I think preloading all 17,000 objects into memory might be risky. There has to be a smarter way to conduct this search to give results back to the user faster.

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• Dynamically writing page titles and active classes with php

  - by toomanyairmiles

  For some time now I've been using the following code to dynamically write in html page titles and add an active class to menu items. Is this still a good why to achieve this or are there better/smarter/optimal ways of achieving the same thing? <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='contact.php'? 'class="active"' : '');?> Menu example <ul id="nav"> <li><a href="index.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='index.php'? 'class="active"' : '');?>><span>Home</span></a></li> <li><a href="services.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services.php'? 'class="active"' : '');?><?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services-landlords.php'? 'class="active"' : '');?><?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services-sellers.php'? 'class="active"' : '');?><?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services-tennants.php'? 'class="active"' : '');?>><span>Our Services</span></a></li> <li><a href="for-sale.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='sales.php'? 'class="active"' : '');?>><span>Sales</span></a></li> <li><a href="to-let.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='lettings.php'? 'class="active"' : '');?>><span>Lettings</span></a></li> <li><a href="register.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='register.php'? 'class="active"' : '');?><?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='register-thanks.php'? 'class="active"' : '');?>><span>Register</span></a></li> <li><a href="contact.php" target="_parent" <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='contact.php'? 'class="active"' : '');?>><span>Contact Us</span></a></li> </ul> Page title Example <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services.php'? 'Services' : '');?> <?php echo (basename($_SERVER['SCRIPT_FILENAME'])=='services-landlords.php'? 'Services for Landlords' : '');?>

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• Reading Source Code Aloud

  - by Jon Purdy

  After seeing this question, I got to thinking about the various challenges that blind programmers face, and how some of them are applicable even to sighted programmers. Particularly, the problem of reading source code aloud gives me pause. I have been programming for most of my life, and I frequently tutor fellow students in programming, most often in C++ or Java. It is uniquely aggravating to try to verbally convey the essential syntax of a C++ expression. The speaker must give either an idiomatic translation into English, or a full specification of the code in verbal longhand, using explicit yet slow terms such as "opening parenthesis", "bitwise and", et cetera. Neither of these solutions is optimal. On the one hand, an idiomatic translation is only useful to a programmer who can de-translate back into the relevant programming code—which is not usually the case when tutoring a student. In turn, education (or simply getting someone up to speed on a project) is the most common situation in which source is read aloud, and there is a very small margin for error. On the other hand, a literal specification is aggravatingly slow. It takes far far longer to say "pound, include, left angle bracket, iostream, right angle bracket, newline" than it does to simply type #include <iostream>. Indeed, most experienced C++ programmers would read this merely as "include iostream", but again, inexperienced programmers abound and literal specifications are sometimes necessary. So I've had an idea for a potential solution to this problem. In C++, there is a finite set of keywords—63—and operators—54, discounting named operators and treating compound assignment operators and prefix versus postfix auto-increment and decrement as distinct. There are just a few types of literal, a similar number of grouping symbols, and the semicolon. Unless I'm utterly mistaken, that's about it. So would it not then be feasible to simply ascribe a concise, unique pronunciation to each of these distinct concepts (including one for whitespace, where it is required) and go from there? Programming languages are far more regular than natural languages, so the pronunciation could be standardised. Speakers of any language would be able to verbally convey C++ code, and due to the regularity and fixity of the language, speech-to-text software could be optimised to accept C++ speech with a high degree of accuracy. So my question is twofold: first, is my solution feasible; and second, does anyone else have other potential solutions? I intend to take suggestions from here and use them to produce a formal paper with an example implementation of my solution.

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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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