Method transposeArray

src/danfojs-base/shared/utils.ts:154–174

* Transposes an array of array * @param obj The object to check. * @param key The key to find.

(arr: ArrayType1D | ArrayType2D)

     * @param key The key to find.
     */
    transposeArray(arr: ArrayType1D | ArrayType2D): ArrayType1D | ArrayType2D { //old name: __get_col_values
        if (arr.length === 0) return arr

        const rowLen: number = arr.length;
        if (Array.isArray(arr[0])) {
            const colLen: number = arr[0].length;
            const newArr = [];

            for (let i = 0; i <= colLen - 1; i++) {
                const temp = [];
                for (let j = 0; j < rowLen; j++) {
                    const _elem = (arr as any)[j][i]
                    temp.push(_elem);
                }
                newArr.push(temp);
            }
            return newArr;
        } else {
            return arr;
        }
    }

    /**
     * Retrieve row array and column names from an object of the form {a: [1,2,3,4], b: [30,20, 30, 20]}