I am trying to draw a scatter chart with equal unit lengths on both axes, but I fail to figure out a proper API or option item to realize this idea.
I have tried another chart framework Chart.js. There I can realize this idea using such trick:
options: {
aspectRatio: size[0] / size[1],
...
}
this property sets the aspect ratio of the chart area(grid area). Here size is the span of both axes, which can be manually derived from:
size[0]=xAxis.max-xAxis.min,
size[1]=yAxis.max-yAxis.min
Though I can't set the unit lengths to same directly, as long as the aspect ratio equals to the proportion of two axes' span, my idea can work out. Here is the desired chart(using Chart.js): equal unit lengths in Chart.js
But here in ECharts, I can't find any API or option item to set either aspectRatio or unit length when plotting a scatter chart. In geo coordinate and series-map, there IS a option item named aspectScale, and I guess it has the same function as aspectRatio in Chart.js according to the documentation. While scatter chart doesn't have such option item. Do I have to bind a geo coordinate to a series-scatter, using a blank SVG, even if I do not need it, so that just for equal unit lengths in a scatter chart?