How to remove NaN from matrix / remove the dark blue pixels in the ocean

Hello everyone,

I have a rainfall plot and the dataset was acquired from APHRODITE. NaN values are located in the ocean regions/basins which is represented by dark blue pixels outside the administrative boundary in the image. Is there a way to completely remove them? Attached here are the plot itself and the matrix. I have tried 'isnan' and 'isinfinite' but none of them work.

Your help is greatly appreciated. Thank you!

Answer 1

[Matt J]

You can't remove the NaNs and keep the original rectangular shape of the matrix without replacing the NaNs with another value, e.g.,

yourMatrix(isnan(yourMatrix)) = 0;

If you don't care about keeping the original rectangular shape, you can just do,

yourMatrix(isnan(yourMatrix)) = [];

[Jianne Pamintuan]

Hello! I tried using both of these codes but it just returns this output:

[Matt J]

There's no way they both return the same output, as seen below:

a=rand(5)>0.5;

yourMatrix=rand(5).*(a./a)

yourMatrix = 5×5

NaN NaN NaN NaN NaN 0.7783 0.3229 0.1825 NaN NaN 0.4769 0.0070 NaN NaN 0.8288 0.0583 NaN NaN NaN NaN NaN NaN NaN NaN 0.8891

A=yourMatrix;
A(isnan(A)) = 0

A = 5×5

0 0 0 0 0 0.7783 0.3229 0.1825 0 0 0.4769 0.0070 0 0 0.8288 0.0583 0 0 0 0 0 0 0 0 0.8891

B=yourMatrix;
B(isnan(B)) = []

B = 1×8

0.7783 0.4769 0.0583 0.3229 0.0070 0.1825 0.8288 0.8891

[Jianne Pamintuan]

I'll try them one more time.

Answer 2

[Walter Roberson]

I suggest you experiment with @John D'Errico FEX contribution https://www.mathworks.com/matlabcentral/fileexchange/4551-inpaint_nans

Answer 3

[Thomas]

Have you try "fillmissing" in newer MATLAB?

>> A = [nan 2 nan 4];

>> A(isnan(A)) = .5

A =

0.5000 2.0000 0.5000 4.0000

>> A = [nan 2 nan 4];

>> fillmissing(A, "constant", 0.4)

ans =

0.4000 2.0000 0.4000 4.0000