MATLAB: How do i fix “inner matrix dimensions must agree” in this formula

divisionfunctionMATLABmatrixmultiplication

I am trying to input a number of variables into a formula which are listed in the code below (r=radial coordinate). I have seen other answers covering this same error but still cannot solve it. i have tried using ./ .* etc. in different places but to no avail. Error is: Error using * Inner matrix dimensions must agree.
Error in project2 (line 19) w=(P*rd^4)./(64*K*(1+v))*(2*(3+v).*(1-(r./rd).^2)-(1+v).*(1-(r./rd).^4))
Can anyone advise as to where my mistake is? Thanks.
Code is:
if true
  % code
end
function [ w,wmax ] = project2( E,K )
%project2 Function to determine deflection (w) at a certain pressure until
%deflection exceeds wmax.
%
v=0.3; %poissons ratio for all materials
t=0.005; %plate thickness, measured in meters
rd=0.15; %plate radius, measured in meters
for P=0:5000:50000;
wmax=P*(rd^4)*(5+v)/64*K*(1+v);
if wmax<=0.0025;
rad=(0:0.01:0.15);
theta=(0:24:360);
[thm, rm]=meshgrid(theta,rad);
[X,Y]=pol2cart(thm,rm);
r=[X,Y];
w=(P*rd^4)./(64*K*(1+v))*(2*(3+v).*(1-(r./rd).^2)-(1+v).*(1-(r./rd).^4))
else pause
end 
end 
end

Best Answer

Some of your defined vectors are of a fixes size, for example:
   rad=(0:0.01:0.15);
   theta=(0:24:360);
Therefore your function is only going to work for scalar inputs (not vectors or matrices) unless you rework the line:
w=(P*rd^4)./(64*K*(1+v))*(2*(3+v).*(1-(r./rd).^2)-(1+v).*(1-(r./rd).^4))
Also your if statement will probably not work as you intend for non scalar inputs as wmax will be the same size as K:
if wmax<=0.0025
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