How can I position a graph cursor via code?

[mpiety]

I am trying to position a waveform graph cursor based on values obtained from other cursors, that is, I know what the Y value is and I want to find the corresponding X value in order to position that cursor on the graph

[BJD1613]

try this example. Hope this helps.

[BJD1613]

you can also read this property to get your x and y values.

[chilly_charly]

First, you have to search for the index number of the Y value. This can be a (relatively) tricky operation if the value is just approximate, and if the Y values do not vary monotonously.
In the simplest case (Y data organized in increasing order), what you have to do is
1/ use the threshold 1D array (in the array subpalette), passing the Y values array and the target Y value as input. The node returns the fractionnal X index. If you need to position the cursor exactly on a data point, round the index value to the nearest integer value.
2/ Move the cursor to the corresponding position using the cursor.index property node

If the Y values are continuously decreasing, reverse the array, then go to step 1.

If the Y values do not vary monotonously, then you
are stuck, and you will be obliged to develop a more elaborate algorithm. Accordingly, your next post to this forum will be :
"How can I find a given value in a 1D array ?"

CC

[chilly_charly]

I just forgot to say that if the Y value is known without uncertainity, the corresponding index value is found using the search 1D array function (also in the Array subpalette). In this case, the Y array does not need to be ordered.
CC