I'm using the d3 parcoords library. When I modify data plotted in a parallel coordinates chart, and reload the chart, the scale of the axis isn't refreshed.
I tried calling .autoscale()
, but if I call it before .render()
, it has no effect, and if I call it after .render()
, then no polylines are drawn anymore.
$("#example").html(""); //to make sure "ghost" axes are removed
parcoords = d3.parcoords()("#example")
.data(parsedData)
.createAxes()
.brushMode("1D-axes")
.reorderable()//;
.detectDimensions()
.dimensions(dimensionObj)
.autoscale() //no visible effect if placed here
.render()
.updateAxes();
Not sure if this is related (although the issue started at the same time), I started specifying an order for the dimensions. To do this, instead of using an array containing the axes (dimensionArray
), I use a JS object dimensionObj
containing numbered "index" keys, as follows:
//dimensionArray = ["axis1", "axis2", "axis3", "axis4"]; //orderless array
//Default axes to display with predefined ordering
dimensionObj = {
"axis1": {index:0},
"axis2": {index:1},
"axis3": {index:2},
"axis4": {index:3}
}
For illustration purposes, the following screenshots show how on the top image, the scales are properly set, but on the second (updated) chart, some new polylines are going to 0 on the 1st and 3rd axis, but the scale isn't updated so lines go out of range.
Is there a simple way to refresh the axis scales when reloading a chart? Is it possible that using the JS object in .dimensions()
is creating some conflicts with the underlying scale function?
Found what was causing this behaviour: an if
statement in d3.parcoords.js pc.autoscale
function which was only resetting scales if the yscale
was not previously defined. Essentially I edited the if
statement from original:
d3.keys(__.dimensions).forEach(function(k) {
if (!__.dimensions[k].yscale){
__.dimensions[k].yscale = defaultScales[__.dimensions[k].type](k);
}
});
to this (of course the if
statement could be dropped altogether, I simply kept it in this form in case I need to revert to original version later for any reason):
d3.keys(__.dimensions).forEach(function(k) {
if (!__.dimensions[k].yscale || __.dimensions[k].yscale){
__.dimensions[k].yscale = defaultScales[__.dimensions[k].type](k);
}
});