Method diag

JSAT/src/jsat/linear/Matrix.java:1009–1019

Returns a new dense square matrix such that the main diagonal contains the values given in a @param a the diagonal values of a matrix @return the diagonal matrix represent by a

(Vec a)

     * @return the diagonal matrix represent by <i>a</i>
     */
    public static Matrix diag(Vec a)
    {
        DenseMatrix A = new DenseMatrix(a.length(), a.length());
        for(Iterator<IndexValue> iter = a.getNonZeroIterator(); iter.hasNext();)
        {
            IndexValue iv = iter.next();
            A.set(iv.getIndex(), iv.getIndex(), iv.getValue());
        }
            
        return A;
    }
    
    /**
     * Alters the matrix <i>A</i> so that it contains the result of <i>A</i>