MATLAB: Can someone tell me what I’m doing wrong. I have looked over this for quite a while already with no success. I think I am messing up when it comes to element by element operation, but I have tried everything I know with no luck.

plotssurf

%this script will plot a 3-D plot of P(v) as a function of v and TM=0.032;R=8.31;x=[0:1000];y=[70:320];[X,Y]=meshgrid(x,y);Z=4*pi*(M/(Y.*2*pi*R)).^(3/2)*(X.^2).*exp((-X.^2*M)./(Y.*2*R))surf(X,Y,Z)xlabel('v (m/s)');ylabel('T (K)');zlabel('P(v)')

• When in doubt, vectorise everything!
This works:
M=0.032;R=8.31;x=[0:1000];y=[70:320];[X,Y]=meshgrid(x,y);Z=4*pi*(M./(Y.*2*pi*R)).^(3/2).*(X.^2).*exp((-X.^2*M)./(Y.*2*R));mesh(X,Y,Z)xlabel('v (m/s)');ylabel('T (K)');zlabel('P(v)')
I replaced your surf call with mesh because the surf plot was so dense it looked completely black (in R2015a).