removeColumn(index) {
            util.checkColumnIndex(this, index);
            if (this.columns === 1) {
                throw new RangeError('A matrix cannot have less than one column');
            }
            for (var i = 0; i < this.rows; i++) {
                this[i].splice(index, 1);
            }
            this.columns -= 1;
            return this;
        }
Removes a column from the given index
@param {number} index - Column index
@return {Matrix} this