MATLAB Answers


Contourf plot of datasets

Asked by Parham Ebrahimi on 15 Aug 2019
Latest activity Commented on by Star Strider
on 16 Aug 2019
Does anyone know how can I have a 2D-contour plot of some given data points?
I have the coordinates inside two vectors x and y. The problem is there is no analyctical function relating the height z, to the coordinates.
I have a seperate vector which has the values of z corrospondig to each (x,y) pair.
I would appreciate if you could help me with this.
Thanks in advance!


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1 Answer

Star Strider
Answer by Star Strider
on 15 Aug 2019
 Accepted Answer

You might find the griddata function useful. It takes random (x,y) values and interpolates gridded z-matrices from them that contour and contourf can use.


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Star Strider
on 16 Aug 2019
My pleasure.
You do not need a function to create ‘Z’, since in your situation ‘Z’ are data you collect. You can create a contour plot of ‘Z’ when you have it as a matrix. If your data are already gridded, you only have to use the reshape function to create matrices from your vectors. Otherwise, you need to use the griddata function to create the ‘Z’ matrix.
If you want to fit a function to your data, that is possible. However, you first need a function that you are reasonably certain describes your data.
You were right. I tried with reshape and it worked. Now I will interpolate to generate more data in the contour.
Star Strider
on 16 Aug 2019
As always, my pleasure!

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