Inner calculation in the frappe.model.set_value(cdt, cdn, ' child form

1

Hello,

I need help again

i am doing math calcualtion in the Child form field , it give me always 0 , i am sure i am doing some mistake

frappe.ui.form.on(‘Purchase Order Item’, ‘sqm’, function(frm, cdt, cdn) {
var def_sqm = 1;
var def_box = 1.44;
var def_pieces = 0.36;
var row = locals[cdt][cdn];
frappe.model.set_value(cdt, cdn, ‘boxes’, row.sqm/def_box);
**** frappe.model.set_value(cdt, cdn, ‘pieces’, [(row.sqm/def_pieces) - (row.boxes*4)]); ***
})

**** When i try to multiple with 4 , it return me 0 value , if i remove 4 then it give proper value , please let me know where i am making mistake,

Thanks again for help

2

Your formula so interesting:
example:
sqm = 2
boxes = sqm/def_box
//boxes = 1.3888888888888888
sqm/def_pieces = 5.555555555555555
boxes * 4 = 5.555555555555555
(sqm/def_pieces) - (boxes*4) = 0