Using experimental database in Matlab for interpolation

Hello, I would like to use an experimental contour plot data in my code for interpolation? I just have picture of this plot. Is there any possibility that I can use this data by using interp2 or something else?

Thank you!

Answer 1

[KL]

Use GRABIT maybe.

https://www.mathworks.com/matlabcentral/fileexchange/7173-grabit

But you'll have to pick the data points manually.

[theintern]

Thank you,

I created my graph and data. But I couldn't solve to use this in my code. And my supervisor told me that I could use interp2 for this job, is it also possible?

[KL]

If you have the data, you don't need this. I thought you only had the image of the data anyway, interp2 is an interpolation function from MATLAB to interpolate values based on the data you have. Check the example on this page.

https://www.mathworks.com/help/matlab/ref/interp2.html

what exactly do you want to do?

[theintern]

Yes, i only have the image of the data.

[theintern]

Now, I see what you mean. I can use GRABIT but after I draw contours how can I write contour line datas?

[KL]

Alright. I'd suggest to use GRABIT first to extract a data matrix and then use interp2 to interpolate more data points and then plot it using contour command.

[theintern]

It worked!! Thank you so much :)

Answer 2

[theintern]

Hello, how can I improve digitized data? I mean there is something wrong as you can see below.

[KL]

Do you mean those points are the results from the interpolation?

Anyway, I don't know what these data represent so I have no idea if there's anything wrong with it.