build/modelscript.umd.js
function(k, U) {
            	var U = U || pca$1(this).U;
            	var Ureduce= U.slice(1, U.rows(), 1, k);
            	return {Z: this.x(Ureduce), U: U};
                }
function(k, U) {
            	var U = U || pca$1(this).U;
            	var Ureduce= U.slice(1, U.rows(), 1, k);
            	return {Z: this.x(Ureduce), U: U};
                }
function ( k , U ) { var U = U || pca$1 ( this ) . U ; var Ureduce = U . slice ( 1 , U . rows ( ) , 1 , k ) ; return { Z : this . x ( Ureduce ) , U : U } ; }
project a matrix onto a lower dim
project a matrix onto a lower dim