How do I get a Value out of a XY Graph

[Wollny91]

Hey there,

I am pretty new to LabView and i hope you can help me out.

I got 2 Arrays both of them got 3 Values and i managed to put them in a XY Graph.

Here is my issue, I want a y value for the corresponding x.

Is there any way to get to that graph data?

Thank you for your efforts in advance.

[natasftw]

You have to feed values into the xy-graph.  Split that wire and bring the data into your logic to get the matching pair.  You already have the dta.  Don't overthink this

[mikeporter]

Yes, but how you do it depends on the datatype of that data driving the graph. You see, an XY graph can plot data in more than 1 format.

Can we see you code?

Mike...

[Wollny91]

Yeah sure, here is my code, its a little bit messy as for now but I think you get what i want.

Its about a temprature meassurement, here is my idea:

I meassured 3 different temperatures and the corresponding Measured Resistance.

Now I got a y value for

9 30 45

plotted the graph -> and now i want a y value for lets say -5 or 15

But i have a hard time actually getting these informations

[altenbach · Accepted solution]

Unless your DAQ data is quantized to the three possble X values, you need to interpolate. You already have made a linear fit, so all you need to do is feed the new x value into "linear evaluation" and get the corresponding y value. Of course you could equally well use e.g. a quadratic polynomial. (For higher orders, you would need more points).

[Wollny91]

OFC thank you so much, i def. overthought that way to much.

It is way easier than i thought it would be.