I&#39;m interested in network analysis on large networks with millions of nodes and tens of millions of edges.  I want to be able to do things like parse networks from many formats, find connected components, detect communities, and run centrality measures like PageRank.

I am attracted to NetworkX because it has a nice api, good documentation, and has been under active development for years.  Plus because it is in python, it should be quick to develop with.

In a recent presentation (the slides are available on github [here][1]), it was claimed that:

&gt; Unlike many other tools, NX is designed to handle data on a scale
relevant to modern problems...Most of the core algorithms in NX rely on extremely fast legacy code.

The presentation also states that the base algorithms of NetworkX are implemented in C/Fortran.

However, looking at the source code, it looks like NetworkX is mostly written in python.  I am not too familiar with the source code, but I am aware of a couple of examples where NetworkX uses numpy to do heavy lifting (which in turn uses C/Fortran to do linear algebra).  For example, the file `networkx/networkx/algorithms/centrality/eigenvector.py` uses numpy to calculate eigenvectors.

Does anyone know if this strategy of calling an optimized library like numpy is really prevalent throughout NetworkX, or if just a few algorithms do it?  Also can anyone describe other scalability issues associated with NetworkX?

**Reply from NetworkX Lead Programmer**
I posed this question on the NetworkX mailing list, and Aric Hagberg replied:

&gt; The data structures used in NetworkX are appropriate for scaling to
&gt; large problems (e.g. the data structure is an adjacency list).  The
&gt; algorithms have various scaling properties but some of the ones you
&gt; mention are usable  (e.g. PageRank,  connected components, are linear
&gt; complexity in the number of edges).
&gt; 
&gt; At this point NetworkX is pure Python code.  The adjacency structure
&gt; is encoded with Python dictionaries which provides great flexibility
&gt; at the expense of memory and computational speed.  Large graphs will
&gt; take a lot of memory and you will eventually run out.
&gt; 
&gt; NetworkX does use NumPy and SciPy for algorithms that are primarily
&gt; based on linear algebra.  In that case the graph is represented
&gt; (copied) as an adjacency matrix using either NumPy matrices or SciPy
&gt; sparse matrices.  Those algorithms can benefit from the legacy C and
&gt; FORTRAN code that is used under the hood in NumPy and SciPY.

  [1]: https://github.com/drewconway/NetworkX_Intro_Materials

What scalability issues are associated with NetworkX?

What is the difference between a ***framework*** and a ***library***? 

I always thought of a library as a set of objects and functions that focuses on solving a particular problem or a specific area of application development (i.e. database access); and a framework on the other hand as a collection of libraries centered on a particular methodology (i.e. MVC) and which covers all areas of application development.

What is the difference between a framework and a library?

I have a binary file - Windows static library (*.lib).  
Is there a simple way to find out names of the functions and their interface from that library ?

Something similar to `emfar` and `elfdump` utilities (on Linux systems) ?

How to See the Contents of Windows library (*.lib)

I am learning C++ and I&#39;ve just started learning about some of [Qt][1]&#39;s capabilities to code GUI programs. I asked myself the following question:

How does C++, which previously had no syntax capable of asking the OS for a window or a way to communicate through networks (with APIs which I don&#39;t completely understand either, I admit) suddenly get such capabilities **through libraries written in C++ themselves?** It all seems terribly circular to me. What C++ instructions could you possibly come up with in those libraries?

I realize this question might seem trivial to an experienced software developer but I&#39;ve been researching for hours without finding any direct response. It&#39;s gotten to the point where I can&#39;t follow the tutorial about Qt because the existence of libraries is incomprehensible to me.


  [1]: https://en.wikipedia.org/wiki/Qt_(software)

How does a language expand itself?

Is there any library which will help me to handle logging in my Node.Js application? All I want to do is, I want to write all logs into a File and also I need an options like rolling out the file after certain size or date. 

---

I have incorporated log4js im trying to keep all the configuration details in one file and use only the methods in other application files for ease of maintenance.  But it doesnt work as expected. Here is what I&#39;m trying to do

    var log4js = require(&#39;log4js&#39;); 
    log4js.clearAppenders()
    log4js.loadAppender(&#39;file&#39;);
    log4js.addAppender(log4js.appenders.file(&#39;test.log&#39;), &#39;test&#39;);
    var logger = log4js.getLogger(&#39;test&#39;);
    logger.setLevel(&#39;ERROR&#39;);
    
    
    var traceLogger = function (message) {
            logger.trace(&#39;message&#39;);
        };
    
    var errorLogger = function (message) {
            logger.trace(message);
        };
    
    
    exports.trace = traceLogger;
    exports.error = errorLogger;

I have included this file in other files and tried

    log.error (&quot;Hello Error Message&quot;);

But it is not working. Is there anything wrong in this ?

Node.js Logging

What are libtool&#39;s `.la` files for? How are they used with a shared object?


What are libtool&#39;s .la file for?

I have a package in R (ROCR) that I need to load in my R environment.  Upon loading the package, a set of messages are printed.  This is ordinarily fine, but since the output of my R script is being used for further analysis I want to completely disable all of this output.  How do I do that?  Furthermore, I&#39;d prefer to do it without having to modify ROCR at all, so that future users of this script don&#39;t have to do that either.

So far:

 - `sink()` doesn&#39;t work here - redirecting both stdout and std err to `/dev/null` does nothing for me.
 - Unsurprisingly, `options(warnings=-1)` does nothing either, since these are not warnings, per se, being printed.

Any thoughts?

Disable messages upon loading a package

I understand Dart compiles to JavaScript, and I read the [Dart Language Spec][1] on Libraries, although I didn&#39;t see an answer there.  Also a search on their [discussion form][2] for the word &#39;existing&#39; turns up 3 results that are not related.

Does anyone know if Dart will support the use of existing JavaScript libraries such as jQuery or Raphael?


  [1]: http://www.dartlang.org/docs/spec/dartLangSpec.pdf
  [2]: https://groups.google.com/a/dartlang.org/group/misc/search?group=misc%C3%A5&amp;q=existing&amp;qt_g=Search%20this%20group

Will Dart support the use of existing JavaScript libraries?

One of the most important rules and best practices when writing a library, is putting all symbols of the
library into a library specific namespace. C++ makes this easy, due to the `namespace` keyword. In
C the usual approach is to prefix the identifiers with some library specific prefix.

Rules of the C standard put some constraints on those (for safe compilation): A C compiler may look at only the first
8 characters of an identifier, so `foobar2k_eggs` and `foobar2k_spam` may be interpreted as the same
identifiers validly – however every modern compiler allows for arbitrary long identifiers, so in our times
(the 21st century) we should not have to bother about this.

But what if you&#39;re facing some libraries of which you cannot change the symbol names / idenfiers? Maybe you got
only a static binary and the headers or don&#39;t want to, or are not allowed to adjust and recompile yourself.


How to deal with symbol collisions between statically linked libraries?

Allergro is an open souce C++ addon library for graphics manipulation. How do I add this library to my compiler?

The instructions don&#39;t work for me as I have Windows 7. I don&#39;t know if the OS matters. I have the Visual Studio Express Edition. The library is a .dll file. How do I add it to my projects?


How to add additional libraries to Visual Studio project?

What is the difference between `.a` `.o` and `.lo` file in C?

Difference between .a .o and .lo file

Since a couple of days, I constantly receive the same error while using MATLAB which happens at some point with `dlopen`. I am pretty new to MATLAB, and that is why I don&#39;t know what to do. Google doesn&#39;t seem to be helping me either. When I try to make an eigenvector, I get this:

    Error using eig
    LAPACK loading error:
    dlopen: cannot load any more object with static TLS

I also get this while making a multiplication: 
  

    Error using  * 
    BLAS loading error:
    dlopen: cannot load any more object with static TLS

I did of course look for the solutions to this problem, but I don&#39;t understand too much and don&#39;t know what to do. These are threads I found:   
   
1. https://stackoverflow.com/questions/1735985/how-do-i-use-the-blas-library-provided-by-matlab   
2. http://www.mathworks.de/de/help/matlab/matlab_external/calling-lapack-and-blas-functions-from-mex-files.html

Can someone help me please?

# Examples of function calls demonstrating this error

    &gt;&gt; randn(3,3)
    
    ans =
    
     2.7694    0.7254   -0.2050             
    -1.3499   -0.0631   -0.1241             
     3.0349    0.7147    1.4897            
       
    &gt;&gt; eig(ans)
    
    Error using eig
    LAPACK loading error:
    dlopen: cannot load any more object with static TLS

MatLab error: cannot open with static TLS

I recently updated my Android Studio (and I&#39;m pretty sure the Gradle version), and now I&#39;ve been getting a bunch of errors when trying to compile my project. Here&#39;s the one that is plaguing me at the moment:

```
Duplicate class android.support.v4.app.INotificationSideChannel found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:26.1.0)
```

This is followed by lots of similar ones.

I tried removing all uses of ```com.android.support``` in favor of androidx (see [here][1] for what I was using the replace things), but ```com.android.support``` libraries are still being used, even when I delete the libraries (they&#39;re just remade once I try to compile again).

[Here&#39;s][2] a link to the full error I get.


  [1]: https://developer.android.com/jetpack/androidx/migrate
  [2]: https://pastebin.com/raw/W7xrRzU8

Duplicate classes from androidx and com.android.support

Other than a nice way to require all files in a directory (https://stackoverflow.com/questions/5364928/node-js-require-all-files-in-a-folder), what is `index.js` used for mainly?

What is index.js used for in node.js projects?

What free and commercial garbage collection libraries are available for C++, and what are the pros and cons of each?

I am interested in hard-won lessons from actual use in the field, not marketing or promotional blurb.

There is no need to elaborate on the usual trade offs associated with automatic garbage collection, but please do mention the algorithms used (reference counting, mark and sweep, incremental, etc.) and briefly summarise the consequences.

Garbage collection Libraries in C++

With PHP you have the [`phpinfo()`](http://php.net/manual/en/function.phpinfo.php) which lists installed modules and then from there look up what they do.

Is there a way to see what packages/modules are installed to import?

Get available modules

Every time I try to import a project downloaded from *googlecode* into Eclipse but I get some errors:

&gt; The project was not built since its build path is incomplete. Cannot
&gt; find the class file for java.lang.Object. Fix the build path then try
&gt; building this project	
&gt; 
&gt; Unable to resolve target &#39;android-10&#39; (this changes from 1 to 15)

I&#39;ve already checked the other answers on the site but no solution worked. 

In 

&gt; Properties -&gt; Java Build Path -&gt; Libraries

 there&#39;s 1 item:

&gt; Unable to get system libraries for the project

The project was not built since its build path is incomplete

I have been working on a project (a game to be specific) and I feel that I should start over with different libraries. So when doing this I reinstalled [Code::Blocks](http://codeblocks.org) and setup my new libraries and includes. 

But as of now Im having a problem starting u[ my new project to test if all of the includes work. This problem is: `libstdc++-6.dll was not found.` At first i wondered if I could just find this file online, but its nowhere to be found(or at least the many places I have searched...) Soon after, I tried loading up my old project, and the same problem happened again(wierd... ._.) I was thinking its maybe my compiler, so I used my older compiler and it did the same thing! At this moment I held the problem off for tomorrow(which is today)

So my question is: If anyone else had this problem, how would you solve it?

Im using Code::Blocks with MinGW as the compiler on Windows Vista 32 bit.


*****EDIT*****

Here are the Build options in my project. Note that these are the settings in the Project, not the global compiler:

In (project name)-&gt;Compiler settings-&gt;Otehr options:

(I use `//` to seperate the commands)

    -mthreads//
    -fmessage-length=0//
    -fexceptions//
    -fident//

In (project name)-&gt;Compiler settings-&gt;#define:


    WIN32//
    _WINDOWS//

In (project name)-&gt;Linker settings-&gt;Other linker options:

    -static-libstdc++//
    -static-libgcc//
    -Wl,--enable-auto-image-base//
    -Wl,--add-stdcall-alias//
    -Wl,--enable-auto-import//

In linker-&gt;link libraries i have various links to files with a `.a` extension, these files include Bullet PHysics, Ogre3D, and SFML

In the search directories i have links to the MinGW/bin, and the MinGW/lib directories, along with other links to different libraries.


My Compiler is MinGW, a GNU GCC compiler for windows 32 bit. and the IDE is Codeblocks. Also note that in Debug and Release settings on the project, there is nothing.

Most of these setings are also pieces that i got from the [Ogre3D Application setup tutorial](http://www.ogre3d.org/tikiwiki/Setting+Up+An+Application+-+CodeBlocks) if that is of any help.



libstdc++-6.dll not found

How do I add local jar files (not yet part of the Maven repository) directly in my project&#39;s library sources?

How to add local jar files to a Maven project?

I&#39;ve just started working with CMake and I noticed that they have both a `find_package` and a `find_library`. And this confuses me. Can somebody explain the difference between a package and a library in the world of programming? Or, in the world of CMake?

Appreciate it, guys!

Package vs Library

I notice a number of java libraries use this as a suffix:

    log4j, couchdb4j, neo4j, launch4j, etc..

All Libraries Solutions on Gang of Coders

Total of 21 Libraries Solutions