comparing lists from two inlets in JavaScript

edsonedge

I want to build a JS object that has two inlets
- each inlet gets a list of varying length's (numbers)
- I then want to compare list a to list b, - so I guess I need to sort the list (making the smallest number come in front, and etc.) but that could also be done before the js object (since I read somewhere that JS in Max doesn't have a sort method ?)
- I want to get TRUE if the shorter list matches the longer list's first numbers (so if list a is (1,2,3) and list b is (1,2,3,4,5) then that should return True (or bang)

I understand how to make a list() function - something like this :

function list()
{
for (i=0; i < arguments.length; i++)
{
post("item ", i+1, "is", arguments[i]+",");
}
}

But I don't know how to go about making a function that takes two lists from two inlets - how do I discern which list is being refered to when I use "arguments"

I've gone through the javascript helpfiles Max offers (which in all honesty are confusing and over-written in my opinion (Max usually having great help files in my opinion)) - but there is very little to be learned there about comparing input data , and even less about how to use more than one inlets (other than, apparently, you can)

do.while

im not at home ,so i cant check it , but it could work for you

function list(){
    if(inlet === 0){
        arr_a = arrayfromargs(arguments) ;
        arr_a.sort(function(a,b){return a-b;})
    }

    if (inlet === 1){
        arr_b = arrayfromargs(arguments) ;
        arr_b.sort(function(a,b){return a-b;})
    }
        if( doCompare() ) outlet(0,"bang");
}

function doCompare(){
    var i , count = 0 ;
    var len_a = arr_a.length ;
    var len_b = arr_b.length ;

    if(len_a >= len_b){
        for(i = 0 , i < len_b ; i++){
            if(arr_b[i] == arr_a[i]){
                count++ ;
            }
        }
        return count == len_b ; 
    }else{
        for(i = 0 , i < len_a ; i++){
            if(arr_a[i] == arr_b[i]){
                count++ ;
            }
        }
        return count == len_a ; 
    }
}

edsonedge

Hi, Thanks a lot for the reply

I get a: Javascript TypeError. ArgumentsInlet is undefined, line 9
and : error calling function list

... line nine is an empty line btw.

Judging from a pure JavaScript perspective your code should work, it seems to me.

do.while

yes , im stupid

autowatch = 1;
inlets = 2 ;
outlets = 1 ;
var arr_a = [] ;
var arr_b = [] ;

function list(){

    if(inlet === 0){
        if(arguments.length){
            arr_a = arrayfromargs(arguments) ;
            arr_a.sort(function(a,b){return a-b;});
        }

    }

    if (inlet === 1){
        if(arguments.length){
            arr_b = arrayfromargs(arguments) ;
            arr_b.sort(function(a,b){return a-b;});
        }

    }
        if( doCompare(arr_a,arr_b) ) outlet(0,"bang") ;

}

function doCompare(a,b){
    var i , count = 0 ;
    var len_a = a.length ;
    var len_b = b.length ;
    if(len_b && len_a){
        if(len_a >= len_b){
            for(i = 0 ; i < len_b ; i++){
                if(b[i] == a[i]){
                    count++ ;
                }
            }
            return count == len_b ; 
        }else{
            for(i = 0 ; i < len_a ; i++){
                if(a[i] == b[i]){
                    count++ ;
                }
            }
            return count == len_a ; 
        }        
    }
    return false ;
}

edsonedge

... You seem pretty smart to me

Thanks a lot! :)

I am wondering... since I am going to have a long list of arrays that I want to compare, and that long list is constantly updating - would it be best to just use coll and have a counter run it - or is there some better compact way, using JS ?

do.while

i believe that you can do similar things with "zl" objects in max directly . check zl.compare ,seems pretty useful !

edsonedge

Yeah, I tried using that, but it doesn't compare lists of differing lengths

I think the js version will be more apt.

Thanks again :)

edsonedge

Sorry to be a pest ... but I am wondering if you can explain a bit what your are doing with this line => arr_b.sort(function(a,b){return a-b;});

The a-b part particularly.

do.while

Hi . dont worry
yes this looks crazy . its a common comparison method for sort() function . if you really want to dig into it then look here ..
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

edsonedge

Thanks :)

do.while

:)))))))))

Emmanuel Jourdan

@edsonedge what do you mean by zl.compare doesn't work when the list have different size? Since they have different size, they are not equal so zl.compare outputs 0. Am I missing something?

edsonedge

I needed to get a comparison function that gets a bang(True) - as long as the longer list contains all the index numbers of the shorter list

But the longer list can then have extra numbers