Method isNa

src/danfojs-base/core/frame.ts:2039–2060

* Return a boolean, same-sized object indicating where elements are empty (NaN, undefined, null). * NaN, undefined and null values gets mapped to true, and everything else gets mapped to false. * @example * ``` * const df = new DataFrame([[1, 2], [3, 4]], { columns: ['A', 'B']})

()

     * ```
    */
    isNa(): DataFrame {
        const newData = []
        for (let i = 0; i < this.values.length; i++) {
            const valueArr = this.values[i] as ArrayType1D
            const tempData = valueArr.map((value) => {
                if (utils.isEmpty(value)) {
                    return true;
                } else {
                    return false;
                }
            })
            newData.push(tempData)
        }

        const df = new DataFrame(newData,
            {
                index: [...this.index],
                columns: [...this.columns],
                config: { ...this.config }
            });
        return df;
    }

    /**
    * Replace all empty elements with a specified value. Replace params expect columns array to map to values array.