cursor hidx to neareset left

[vinnitu]

Hi!

In a stepped chart I want to show the same nearest left point as selected in both cases.

How to handle it with dataIdx?

[leeoniya]

take a look at https://github.com/leeoniya/uPlot/blob/master/demos/nearest-non-null.html

you'd just exclude the right value search loop.

[vinnitu]

here is all values is defined (not one null)

[leeoniya]

you said in another issue that you also had null and undefined values.

anyways, in dataIdx(), you'll want to grab self.cursor.left and pass it to self.posToVal() this will give you an exact value along x at the cursor position. then you can test the distance to the current and adjacent indices' values to make the decision which index to return.

[leeoniya]

i've added a raw xValue parameter to dataIdx() that simplifies this implementation. i've added this behavior to the stepped-line demo:

https://leeoniya.github.io/uPlot/demos/line-stepped.html