ECharts numbers a cell by axis index, not by name, and a category y
axis runs bottom-up -- measured, a 2x2 grid reports its four cells as
[0,0], [0,1], [1,0], [1,1] with y = 0 at the bottom.
HeatmapData.y and points are top-first, so the rows are turned over on
the way out.
A cell the chart drew nothing at stays null rather than becoming a zero:
a grid is a rectangle and the data need not fill it (#1191).
Builds the layer for one heatmap series.
ECharts numbers a cell by axis index, not by name, and a category y axis runs bottom-up -- measured, a 2x2 grid reports its four cells as
[0,0],[0,1],[1,0],[1,1]withy = 0at the bottom.HeatmapData.yandpointsare top-first, so the rows are turned over on the way out.A cell the chart drew nothing at stays
nullrather than becoming a zero: a grid is a rectangle and the data need not fill it (#1191).