reversescale doesn't reverse colorbar on contour plot with coloring='heatmap'

[harupy]

Bug

reversescale: True doesn't reverse the colorbar on a contour plot with {contours: {coloring: 'heatmap'}}.

In the plot below, the colorbar indicates the red region has larger values, but it actually has smaller values.

Code

var data = [{
 z: [[10, 10.625, 12.5, 15.625, 20],
 [5.625, 6.25, 8.125, 11.25, 15.625],
 [2.5, 3.125, 5., 8.125, 12.5],
 [0.625, 1.25, 3.125, 6.25, 10.625],
 [0, 0.625, 2.5, 5.625, 10]],
 x: [-9, -6, -5 , -3, -1],
 y: [0, 1, 4, 5, 7],
 type: 'contour',
 contours: {
 coloring: 'heatmap'
 },
 reversescale: true,
}];

var layout = {
 title: 'Setting the X and Y Coordinates in a Contour Plot'
};

Plotly.newPlot('myDiv', data, layout);

Codepen

https://codepen.io/harupy/pen/bGNgBOz

[harupy]

Without {contours: {coloring: 'heatmap'}}, it works.

Code

var data = [{
 z: [[10, 10.625, 12.5, 15.625, 20],
 [5.625, 6.25, 8.125, 11.25, 15.625],
 [2.5, 3.125, 5., 8.125, 12.5],
 [0.625, 1.25, 3.125, 6.25, 10.625],
 [0, 0.625, 2.5, 5.625, 10]],
 x: [-9, -6, -5 , -3, -1],
 y: [0, 1, 4, 5, 7],
 type: 'contour',
 reversescale: true,
}];

var layout = {
 title: 'Setting the X and Y Coordinates in a Contour Plot'
};

Plotly.newPlot('myDiv', data, layout);

Codepen

https://codepen.io/harupy/pen/NWPddqQ

[harupy]

plotly.js/src/traces/contour/colorbar.js

Lines 22 to 28 in adf9bee

	if(coloring === 'heatmap') {
	var cOpts = extractOpts(trace);
	opts._fillgradient = trace.colorscale;
	opts._zrange = [cOpts.min, cOpts.max];
	} else if(coloring === 'fill') {
	opts._fillcolor = colorMap;
	}

Do we need to flip the colorscale here like below?

 if(coloring === 'heatmap') {
 var cOpts = extractOpts(trace);

 opts._fillgradient = cOpts.reversescale ?
 Colorscale.flipScale(cOpts.colorscale) :
 cOpts.colorscale;

 opts._zrange = [cOpts.min, cOpts.max];
 } else if(coloring === 'fill') {
 opts._fillcolor = colorMap;
 }

It seems to be working.

the json to produce the plot above:

{
 "data": [
 {
 "z": [
 [10, 10.625, 12.5, 15.625, 20],
 [5.625, 6.25, 8.125, 11.25, 15.625],
 [2.5, 3.125, 5, 8.125, 12.5],
 [0.625, 1.25, 3.125, 6.25, 10.625],
 [0, 0.625, 2.5, 5.625, 10]
 ],
 "x": [-9, -6, -5, -3, -1],
 "y": [0, 1, 4, 5, 7],
 "type": "contour",
 "contours": {
 "coloring": "heatmap"
 },
 "reversescale": true
 }
 ]
}

[etpinard]

Thanks for reporting!

[harupy]

@etpinard Thanks!