D3 fill transition for heatmap not working
问题 I'm trying to create a modified version of Mike Bostock's calendar view (https://bl.ocks.org/mbostock/4063318), which only shows a few months. I'm almost there, but I'd like to add a short transition when the individual cells are filled. I tried to create this but it isn't transitioning. I must be missing something obvious. Any ideas? Thanks! Here is the script (see the line ".transition().duration(1000)"): <script src="https://d3js.org/d3.v4.min.js"></script> <script> var width = 550, height