Smoothing contour plot of isotherm

Hi i have an argo data and I'm trying to make isotherm line. I choose 1999~2004 winter data and interpolation 1m.

And I want to more smooth isotherm line. Additionally, I'm so beginner of matlab. Thank you for considering.

• And Zi has NaN values, I guess this is cause. Why my zi has NaN......

[AndresVar]

I have question about removing nan from b. The shape of b is 2D right? Otherwise it could have large discontinuity.

Instead of interp1 you could try the Damien Garcia's inpaint (for 2D b):

Inpaint over missing data in 1-D, 2-D, 3-D,... ND arrays - File Exchange - MATLAB Central (mathworks.com)

Or

Gridded data interpolation - MATLAB (mathworks.com)

smoothn - File Exchange - MATLAB Central (mathworks.com)

I am not familiar for why griddata gives you nan, could it be because b is not smooth and has very large noise.

Answer 1

[DGM]

I don't have your data, and your code is a picture, so I can't do anything with it.

That said, it looks like the problem is merely the size of the ZData.

Consider the example:

Z = peaks(10); % a very small array
contourf(Z,10);

figure
Z = peaks(100); % a larger array
contourf(Z,10);

You should be able to change this resolution by reducing the stepsize when you generate the Xp and Yp vectors.

[주희 박]

Wow It's simple and very useful method! Thank you so much!!

[DGM]

If you find that the answer satisfies your question to your satisfaction, you can click Accept. That way the question will be moved to the "answered" queue, where it may be more valuable to the next person searching for help with a similar problem.