v0.6.2

Please see the 0.6.2 release notes for more!

• Add raster and contour marks. #1196
• Add shape option to vector mark. #1189
• Add spike convenience constructor. #1189
• Add centroid and geoCentroid transforms. #1189
• Add identity helper.
• Add named time intervals. #1205
• Greatly improve the performance of the bin transform. #1225
• Fix descending domains on diverging scales. #1188
• Fix frame clip option for band scales. #1204
• Fix a crash when a facet scale’s domain includes a value for which there is no corresponding facet data. #1216
• Limit generated SVG path data to three fractional digits. #1193 #1203
• Add a helpful error when the stack order option is used without a z channel. #1209
• Fix the group, bin, and hexbin transforms to ignore undefined outputs. #1230