A point from a graph

[TeoLupu]

Hi. 

Do you know how can i find a point from a XY graph?..I know the Y coordinate and I want to find the X coordinate. My point is 0.9347. With interpolate? Any ideas?

[nitad54448]

Hi

You can do that (but you should not have two or more equal values of Y in your graph.... or if you do, you can select which x to obtain).

The simplest way (I think) to do it is to find the 2 or 3 nearest points of Y, close to your selected value, then obtain the line or polynomial coefficients and calculate x.

N

[altenbach]

Assuming the data is non-descending, you can use threshold array. If you represent your xy data as an array of points, it will be easiest.

Can you show us how the xy data is currently wired to the graph (complex, cluster of x and y arrays, array of xy points, etc.)

[nitad54448 · Accepted solution]

Hi again

Depending upon the number of points you have to search and what resolution, a simple search (might be time consuming) can be used. See attached vi

[TeoLupu]

Technically I have some mean numbers which correspond to kg number..First 5 values I know that they are for 1-5kg. For the last one I have just the mean number and I know is between 3 - 4 kg. That's why i want to find it from the graph.

[nitad54448]

Hi

Have you tried the VI that I attached ?

N

[TeoLupu]

I have LabView 15. 

[RavensFan]

Nitad's VI in LV 15.

[RavensFan]

Nitad's post should be marked as the solution.  All I did was convert it for you.