max.hhs

/**
 * @author Jason Reynolds
 * @param input - the structure to find the maximum value of. Can be a list, 1d array, 2d array, Mat, Tensor, number, etc
 * max(1, 2, 3) or max([1, 2, 3])
 * @returns - a number that is the maximum value in the structure
 * 
 * Function that finds the maximum value of a list, matrix or general matrix like structure
 * 
 */



function max(input) {

    *import math: is_number
    *import math: flatten

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

    // max(1, 2, 3)
    if (arguments.length > 1) {
        let result = arguments[0];
        for (let i = 0; i < arguments.length; i++) {
            if (!is_number(arguments[i])) {
                throw new Error('Exception occurred in max - only numbers can be compared');
            }

            if (result < arguments[i]) {
                result = arguments[i];
            }
        }
        return result;
    }

    if (is_number(input)) {
        return input;
    }

    if (!(Array.isArray(input)) && !(input instanceof Mat) && !(input instanceof Tensor)) {
        throw new Error('Exception occurred in max - input can only be number, JS array, matrix or tensor');
    }

    //declare raw_in as the clone of input if a Mat/Tensor otherwise, input itself
    let in_type = (input instanceof Mat || input instanceof Tensor);
    let raw_in = (in_type) ? input.clone().val : input;
    // let raw_in be a 1-d array
    raw_in = flatten(raw_in);
    
    // in case raw_in === []
    if (raw_in.length === 0) {
        return 0;
    }
    let result = raw_in[0];
    for (let i = 0; i < raw_in.length; i++) {
        if (!is_number(raw_in[i])) {
            throw new Error('Exception occurred in max - only numbers can be compared');
        }

        if (result < raw_in[i]) {
            result = raw_in[i];
        }
    }
    return result;
}