build/modelscript.umd.js
function(k) {
            	if(!k)
            	    k = 0;
            	
            	return this.map(function(x, i, j) {
            	    return j - i >= k ? x : 0;
            	});
                }
function(k) {
            	if(!k)
            	    k = 0;
            	
            	return this.map(function(x, i, j) {
            	    return j - i >= k ? x : 0;
            	});
                }
function ( k ) { if ( ! k ) k = 0 ; return this . map ( function ( x , i , j ) { return j - i >= k ? x : 0 ; } ) ; }
grab the upper triangular part of the matrix
grab the upper triangular part of the matrix