Swap rows with columns (transposition) of a matrix in javascript -

for instance have matrix this:

|1 2 3|     |4 5 6| |7 8 9| 

and need convert matrix this:

|1 4 7|     |2 5 8| |3 6 9| 

what best , optimal way achieve goal?

see article: transpose array in javascript , jquery

function transpose(a) {      // calculate width , height of array    var w = a.length || 0;    var h = a[0] instanceof array ? a[0].length : 0;      // in case 0 matrix, no transpose routine needed.    if(h === 0 || w === 0) { return []; }      /**     * @var {number} counter     * @var {number} j counter     * @var {array} t transposed data stored in array.     */    var i, j, t = [];      // loop through every item in outer array (height)    for(i=0; i<h; i++) {        // insert new row (array)      t[i] = [];        // loop through every item per item in outer array (width)      for(j=0; j<w; j++) {          // save transposed data.        t[i][j] = a[j][i];      }    }      return t;  }    console.log(transpose([[1,2,3],[4,5,6],[7,8,9]]));