Browser crash - Too many ticks added when min and max are of similar values

[JacquiManzi]

The problem exists on line 7230 in envision.js in the extendYRange function.

As an example, two values of min and max are compared... let's use:

o min = 18.0001530072
o max = 18.0001530082

Let's use 2 for our line width and we get this:

o range = (max-min) //1.000000082740371e-9
o max += 2 * 0.01 //18.0201530082
o min -= 2*0.01 //17.980153007200002
o newRange = (min-max) //0.04000000099999923
o newRange / range //39999997.69038458

As shown above, 39999997.69038458 is the number of ticks that will be added to Y Axis. This causes the browser to freeze and crash.

Function in question:

extendYRange : function (axis, data, options, lines) {

var o = axis.options;

// HACK
if ((!o.max && o.max !== 0) || (!o.min && o.min !== 0)) {
  axis.max += options.lineWidth * 0.01;
  axis.min -= options.lineWidth * 0.01;
  /*
  axis.max = axis.p2d((axis.d2p(axis.max) + options.lineWidth));
  axis.min = axis.p2d((axis.d2p(axis.max) - options.lineWidth));
  */
}

}
});

I have modified this in my code base to resolve the issue for myself. I am now scaling the tick size with the axis range:

// HACK
var numTicks = (axis.max-axis.min)/axis.tickSize;
if ((!o.max && o.max !== 0) || (!o.min && o.min !== 0)) {
axis.max += options.lineWidth * 0.01;
axis.min -= options.lineWidth * 0.01;

//JMM: Added this because increasing the min/max when numbers with very little difference between min and max (e.g 1e-9) meant that the size of the adjustment above caused millions of ticks to be generated. So, we need to scale the tick size with the axis range.
if((axis.max - axis.min)/axis.tickSize > numTicks)
{
axis.tickSize = (axis.max-axis.min)/numTicks;
}
/*
axis.max = axis.p2d((axis.d2p(axis.max) + options.lineWidth));
axis.min = axis.p2d((axis.d2p(axis.max) - options.lineWidth));
*/
}
}
});

This is what I did to fix this, but am not sure if this is a good general solution since I am not sure why the range is being extended in the first place.

Thanks!
-Jacqui