Introduction

Now you can also use dynamic chivectors as your vertex-data type. The basic usage is similar to DynamicEdgeData, so please read that tutorial first.

Usage

There is currently no example application which uses dynamic vertex data, but there is a test code that does: http://code.google.com/p/graphchi/source/browse/src/tests/test_dynamicedata_loader.cpp

To enable dynamic vertex data, you need to define in the beginning of your source code:

#define DYNAMICVERTEXDATA 1


Then define the vertex datatype: typedef chivector<size_t> VertexDataType;

You can replace size_t with any primitive or struct type.

Here is example how to add and read values from the vertex's vector:

``` chivector * vvector = vertex.get_vector(); int numitems = vertex.id() % 10; for(int i=0; iadd(i); // Arbitrary }

     /* Check vertex data immediatelly */
     for(int i=0; i<numitems; i++) {
        assert(vvector->get(i) == i);
     }

```

No, that instead of get_data(), you call get_vector() for the vertex object.

Accessing vertex data after computation

After your computation has finished, you can access the vertex values by using vertex-data iterator callback.

Here is example:

VertexValidator validator; foreach_vertices(filename, 0, engine.num_vertices(), validator);

Here validator is a callback object:

``` class VertexValidator : public VCallback > { public: virtual void callback(vid_t vertex_id, chivector &vec) { int numitems = vertex_id % 10; assert(vec.size() == numitems);

    for(int j=0; j < numitems; j++) {
        size_t x = vec.get(j);
        assert(x == j);
    }
}

}; ```

For example, if you want to output your results into a text-file, you simply implement file writing inside the callback.