/* https://www.sololearn.com/Discuss/463735/?ref=app */ function new_arr(row, col, init=0) { var c, i, j = row; var m = []; while (j--) { m.push([]); c = m.length-1; i = col; while (i--) m[c].push(init); } return m; } function mult_arr(m1,m2) { if (m1[0].length!=m2.length) return null; // no compatible matrix var row = m1.length; var col = m2[0].length; var com = m2.length; m = new_arr(row,col); var i, j = row; while (j--) { i = col; while (i--) { k = com; while (k--) m[j][i] += m1[j][k]*m2[k][i]; } } return m; } function hadamard_mult_arr(m1, m2, row, col) { var i, j = row; var m = new_arr(row,col); while (j--) { i = col; while (i--) m[j][i] = m1[j][i]*m2[j][i]; } return m; } function scalar_mult(n,m,row,col) { var i, j = row; var nm = new_arr(row,col); while (j--) { i = col; while (i--) nm[j][i] = m[j][i]*n; } return nm; } function kronecker_mult_arr(m1, m2) { var r1 = m1.length; var r2 = m2.length; var c1 = m1[0].length; var c2 = m2[0].length; var row = r1*r2; var col = c1*c2; var m = new_arr(row,col); var i, j = row; while (j--) { i = col; while (i--) m[j][i] = m1[Math.floor(j/r1)][Math.floor(i/c1)]*m2[j%r2][i%c2]; } return m; } /* addition adapted from: http://www.dailyfreecode.com/code/matrix-addition-function-2227.aspx */ function read_arr(a, row, col) { var i, j; for (j=0; j'; document.body.innerHTML += 'B:

'+print_arr(m2,row,col)+'

'; document.body.innerHTML += 'A+B:

'+print_arr(m3,row,col)+'

'; /* multiplication */ m3 = hadamard_mult_arr(m1,m2,row,col); document.body.innerHTML += 'A•B (Hadamard multiplication):

'+print_arr(m3,row,col)+'

'; m3 = kronecker_mult_arr(m1,m2); document.body.innerHTML += 'A⊗B (Kronecker multiplication):

'+print_arr(m3,row*row,col*col)+'

'; m1 = [[1,2,0],[4,3,-1]]; m2 = [[5,1],[2,3],[3,4]]; m3 = mult_arr(m1,m2); document.body.innerHTML += 'C:

'+print_arr(m1,2,3)+'

'; document.body.innerHTML += 'D:

'+print_arr(m2,3,2)+'

'; document.body.innerHTML += 'C×D: (common matrix multiplication)

'+print_arr(m3,2,2)+'

'; m3 = mult_arr(m2,m1); document.body.innerHTML += 'D×C: (common matrix multiplication)

'+print_arr(m3,3,3)+'

'; m1 = [[1,2],[3,1]]; m2 = [[0,3],[2,1]]; m3 = kronecker_mult_arr(m1,m2); document.body.innerHTML += 'E:

'+print_arr(m1,2,2)+'

'; document.body.innerHTML += 'F:

'+print_arr(m2,2,2)+'

'; document.body.innerHTML += 'E⊗F: (Kronecker multiplication)

'+print_arr(m3,4,4)+'

'; };

Matrix Addition and Multiplication Functions [vanilla JS]