GUI: update interval fails for "with add"

[PrometheusPi]

I tested isaac using the default KHI example (with gamma=3).

In order to plot the particle momentum according to the min max range, I used the "With add" option to automatically optimize the range. However, the new range did not stick to the plotable range of [0-1] but went outside the plotable range. There seems to be an issue with this new range. I will provide screen shots below.

[PrometheusPi]

Range set manual:

(not ideal setting - since it is slightly below zero)

Range set automatically:
starting from mul(1,0,0) (only x-component of momentum) then pressing (with "With add")

starting from idem (also x-component of momentum only) then pressing (with "With add")
it looks better but does not give useful ranges

[PrometheusPi]

One part of the issue seems to come from that fact that adding add(0.5) on a vector quantity actually means add( 0.5, 0.5, 0.5), which of course, if you just rescaled values with mul(x) to ( [-1,+1], ~0, ~0 ) - that you now end up with ( [-0.5,+1.5], ~0.5, ~0.5 ) - which is exactly what one gets one optimizing automatically with "With add".

[PrometheusPi]

The relevant code is here:

isaac/client/js/isaac/interface/visualisation.js

Lines 363 to 374 in 8cf6133

	function createOptimizedFunction(i, minmax, with_add) {
	return function () {
	var mul = 1 / (minmax["max"] - minmax["min"]);
	var function_string = document.getElementById("f_" + i + "_string");
	if (function_string.value == "idem" || function_string.value == "")
	functions[i] = "mul(" + mul.toFixed(5) + ")";
	else
	functions[i] = function_string.value + " | mul(" + mul.toFixed(5) + ")";
	if (with_add)
	functions[i] += " | add(0.5)";
	function_string.value = functions[i];
	};