is_missing.hhs

/**
 * @author Jianan Lin (林家南)
 * @param input - an array, matrix, tensor that you want to find missing element
 * @returns - a matrix or tensor with same size, element is 1 or 0 depending on missing or not
 * A missing element is NaN, null, '', or undefined. Notice [] and {} are not missing.
 * 
 */



function is_missing(input) {

    *import math: ndim
    *import math: deep_copy

    // argument check
    if (arguments.length === 0) {
        throw new Error('Exception occurred in is_missing - no argument given');
    }

    if (arguments.length > 1) {
        throw new Error('Exception occurred in is_missing - wrong argument number');
    }

    if (!(Array.isArray(input)) && !(input instanceof Mat) && !(input instanceof Tensor)) {
        throw new Error('Exception occurred in is_missing - input must be an array, matrix or tensor');
    }

    let in_type = input instanceof Mat || input instanceof Tensor;
    let raw_in = in_type ? input.clone().val : deep_copy(input);
    let result = deep_copy(raw_in);
    ismissing_helper(raw_in, result);
    if (ndim(result) <= 2) {
        return mat(result);
    }
    else {
        return new Tensor(result);
    }

    function ismissing_helper(raw_in, result) {
        if (ndim(raw_in) === 1) {
            for (let i = 0; i < raw_in.length; i++) {
                if (raw_in[i] || raw_in[i] === 0) {
                    result[i] = 0;
                }
                else {
                    result[i] = 1
                }
            }
            return;
        }

        else {
            for (let i = 0; i < raw_in.length; i++) {
                ismissing_helper(raw_in[i], result[i]);
            }
            return;
        }
    }
}