Add row and column methods to CommonOps about efficient-java-matrix-library HOT 4 CLOSED

An easy way (but perhaps naive, performance wise) is:

public static SimpleMatrix rowTotals(SimpleMatrix A) { 
        SimpleMatrix l = new SimpleMatrix(1, A.numCols()); 
        l.set(1.0); 
        return l.mult(A.transpose()).transpose(); 
} 

public static SimpleMatrix columnTotals(SimpleMatrix A) { 
        SimpleMatrix l = new SimpleMatrix(1, A.numRows()); 
        l.set(1.0); 
        return l.mult(A).transpose(); 
} 

Which is a simple trick to get the totals. The final transpose is 
there just to get vertical vectors in stead of horizontal ones. I'm 
not sure if this is the most efficient way in ejml or if iteration is 
faster. Feel free to reuse. 

I remember you mentioned this before.  I'll add something similar to CommonOps.

Similar functions have been added to CommonOps.  Take a look at sumRows() and 
sumCols() in common ops.  A more direct method was used to compute the output 
which should be faster.

Assuming that the functions added are sufficient.  Will reopen if this is not 
the case.