How can I plot the contour lines between two spheres ?

I want to plot contours between the spheres

[Adam Danz]

There's an error in your attached file, test2.m. There's an undefined variable a in line 10.

c =-a/L; % line 10

test2()

Unrecognized function or variable 'a'.

Error in test2 (line 10)
c =-a/L;

[Adam Danz]

I've never seen a file with such long lines of code.

This file has 81 lines of code and 193,501 characters.

Line 4 has over 45,000 characters.

Line 5 has nearly 70,000 characters.

This seems like a red flag. It's unreadble. It's very likely that much of it can be simplified. I'm curious how the file was generated.

[Shreen El-Sapa]

The above file contains draft data. I will rewrite the true and excute.

Thanks for your help and comments.

[Star Strider]

Reference: how can I plot the contours inside not outside?

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[Shreen El-Sapa]

I want the sreamlines cover the region, sketch around the inside sphere

If you can help me