i am making using of the jama package for finding the lsa . I was told to reduce the dimensionality and hence i have reduced it to 3 in this case and i reconstruct the matrix . But the resultant matrix is very different from the one i had given to the system
heres the code
a = new Matrix(termdoc); // get the matrix here
a = a.transpose() ; // since the matrix is in the form of doc * terms i transpose it
SingularValueDecomposition sv =new SingularValueDecomposition(a) ;
u = sv.getU();
v = sv.getV();
s = sv.getS();
uarray = u.getArray();
sarray = s.getArray();
varray = v.getArray();
sarray_mod = new double[3][3]; //reducing dimension
uarray_mod = new double[uarray.length][3];
varray_mod = new double[3][varray.length];
move(sarray,3,3,sarray_mod); // my method to move the contents
move(uarray,uarray.length,3,uarray_mod);
move(varray,3,varray.length,varray_mod);
e = new Matrix(uarray_mod);
f = new Matrix(sarray_mod);
g = new Matrix(varray_mod);
Matrix temp =e.times(f);
result = temp.times(g);
result = result.transpose();
results = result.getArray() ;
System.out.println(" The array after svd : \n");
print(results);// my method to print the array
private static void move(double[][] sarray2, int r, int c,
double[][] sarrayMod) {
// TODO Auto-generated method stub
for(int i=0;i<r;i++)
for(int t=0;t<c;t++)
sarrayMod[i][t]=sarray2[i][t];
}
A sample output with just 3 files of which two are the similar
0.25 0 0 0 0 0 0 0 0.25 0 0.25 0.25 0
0 0.083 0.083 0.083 0.083 0.083 0.083 0.083 0 0.083 0.083 0.167 0.083
0.25 0 0 0 0 0 0 0 0.25 0 0.25 0.25 0
The array after svd :
0.225 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.225 0.029 0.253 0.282 0.029
-0.121 0.077 0.077 0.077 0.077 0.077 0.077 0.077 -0.121 0.077 -0.044 0.033 0.077
0.245 0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.245 0.012 0.257 0.269 0.012