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Update Math.js to fix Issue 256 #257

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Update Math.js to fix Issue 256 #257

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690e420
Update Math.js to fix Issue 256
lgto4 Jul 19, 2016
a4352a8
Incorporate Pomax's feedback
lgto4 Aug 1, 2016
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41 changes: 20 additions & 21 deletions src/P5Functions/Math.js
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Original file line number Diff line number Diff line change
Expand Up @@ -411,40 +411,39 @@ module.exports = function withMath(p, undef) {

/**
* Generates random numbers. Each time the random() function is called, it returns an unexpected value within
* the specified range. If one parameter is passed to the function it will return a float between zero and the
* value of the high parameter. The function call random(5) returns values between 0 and 5 (starting at zero,
* the specified range. If one parameter is passed to the function it will return a float between zero and
* that value. The function call random(5) returns values between 0 and 5 (starting at zero,
* up to but not including 5). If two parameters are passed, it will return a float with a value between the
* parameters. The function call random(-5, 10.2) returns values starting at -5 up to (but not including) 10.2.
* To convert a floating-point random number to an integer, use the int() function.
*
* @param {int|float} value1 if one parameter is used, the top end to random from, if two params the low end
* @param {int|float} value2 the top end of the random range
* @param {int|float} value1 if one parameter is used, the end of the range, if two params the beginning
* @param {int|float} value2 the end of the random range
*
* @returns {float}
*
* @see randomSeed
* @see noise
*/
p.random = function() {
if(arguments.length === 0) {
return internalRandomGenerator();
p.random = function(a, b) {
a = a || 0;
if (arguments.length === 0) {
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with named arguments, we can simplify a little more:

if (arguments.length === 1) {
  b = a;
  a = 0;
} else {
  a = a || 0;
  b = b || 1;
}

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You cannot do b = b || 1; ! That well mess up invocations like random(-5, 0);

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@Pomax Pomax Aug 2, 2016 •
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that is a good point. But we can do b = (typeof b !== 'undefined') ? b : 1 (really wish there was a pragma that made truthiness easier in JS in that respect...)

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@GoToLoop GoToLoop Aug 2, 2016 •
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No need to rely on operator typeof for parameter variables. We can test for 'em directly.
Also, it's much safer to catch null as well by using != instead of !==:
b = b != null? b : 1 or b = b != undefined? b : 1 or b = b != void 0? b : 1

Other alternatives:
b = b == null && 1 || b or b = b == undefined && 1 || b or b = b == void 0 && 1 || b

Or even the good old if ():
if (b == null) b = 1 or if (b == undefined) b = 1 or if (b == void 0) b = 1

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Yep, the different ways to it correctly is only slightly less than all the ways to do it incorrectly. So I'm leaving my second iteration as is.

b = 1;
} else if (arguments.length === 1) {
b = a;
a = 0;
}
if(arguments.length === 1) {
return internalRandomGenerator() * arguments[0];
}
var aMin = arguments[0], aMax = arguments[1];
if (aMin === aMax) {
return aMin;
}
for (var i = 0; i < 100; i++) {
var ir = internalRandomGenerator();
var result = ir * (aMax - aMin) + aMin;
if (result !== aMax) {
return result;
if (a !== b) {
for (var i = 0; i < 100; i++) {
var ir = internalRandomGenerator();
var results = ir * (b - a) + a;
if (results !== b) {
return results;
}
// assertion: ir is never less than 0.5
}
// assertion: ir is never less than 0.5
}
return aMin;
return a;
};

// Pseudo-random generator
Expand Down