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## Re: How to get the Z value of a point (X,Y) from surface plot?

 From: Burak Kaymakci Subject: Re: How to get the Z value of a point (X,Y) from surface plot? Date: Sat, 20 Jul 2019 00:24:57 +0200

Oh okay, sorry, I didn't know it is not being sent. I will do it from now on.
Thank you for the answers and the warning. :)

If I find anything, I can mail it again.

Brett Green <address@hidden>, 20 Tem 2019 Cmt, 00:22 tarihinde şunu yazdı:
Unfortunately, that I don't know. If you're fine with just linear interpolation, you could calculate it by hand that way, but that's the best I can suggest offhand.

By the way, please use reply all so these are sent to the mailing list too - maybe someone else will know an easy way to do this.

- Brett Green

On Fri, Jul 19, 2019 at 5:48 PM Burak Kaymakci <address@hidden> wrote:
But what if I want an index that is not in my matrices A, and B but within the range?

Brett Green <address@hidden>, 19 Tem 2019 Cum, 23:33 tarihinde şunu yazdı:
Yes, Burak - I didn't mean calling C(A(1), B(2)) like you said. What I said was that you need to find which indices correspond to that X value. For example, if Y=9, then you would want to find out i such that B(i)=9. In your example, i=3. You can do this with e.g. "yindex = find(B==9)".

(Please excuse me for forgetting the transposition with surf indexed as C(j,i) there.)

- Brett Green

On Fri, Jul 19, 2019 at 5:22 PM Doug Stewart <address@hidden> wrote:

On Fri, Jul 19, 2019 at 4:45 PM Burak Kaymakci <address@hidden> wrote:
How can I get the Z value of a given point (X, Y) on a surface plot using octave-cli?

I am creating a simple surface plot using the code below. I am just playing around with the functions and plots to see what I can do and understand how to use them.

A = [1 2 3 4 5 6];
B = [7 8 9 10 11 12];
C = magic(6);

surf(A, B, C);

What I want is to get the value of a given point (X, Y) from the surface plot I've created with the given code above.

For example, on MATLAB you can get a value by hovering over a point on the plot, like in below screenshot. But on Octave when you hover over the plot you just get (X, Y) values.

Actually when you use `Z1 = interp2(A, B, C, X1, Y1)`, you can get the result too, but, as far as I know, this is not getting the data from the plot.

try this

A = [1 2 3 4 5 6];
B = [7 8 9 10 11 12];
C = magic(6);

h=surf(A, B, C);
q=get(h)
q.zdata

--
DAS 