Operation Order and Matrix Agreement Not working

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This code will not run with the error "inner matrix dimensions must agree".I am not sure is the fomulas are written out completely. This utilizes the Deflection equations found here (It is a pdf of multiple deflection equations):
I used the formulas on: 2, 3, 7, 8
I is the moment of Inertia L is the actual Length of the beam b is the width of the beam x is the points to test on a beam // this is saved a a vector 0 is omega which is the Force(Magnitude) divided by the Length of the beam
Please help if you can understand this or know what is wrong.
I = z.Inertia;
L = z.Length;
b = z.Width;
x = linspace(0,z.Length);
o = z.Magnitude/z.Length; % Magnitude is them same as the force
if z.Load == 1
if z.Support == 1
Beam.y1 = (F*x.^2/6*E*I)*(3*a-x); % 0<x<a
Beam.y2 = (F*a^2/6*E*I)*(3*x-a); % a<x<L
else % x.Support == 2
Beam.y1 = (F*b*x/6*L*E*I)*(L^2-x.^2-b^2); % 0<x<a
Beam.y2 = (F*b/6*E*L*I)*((L/b)*(x-a)^3+(L^2-b^2)*x-x.^3); % a<x<L
else % x.Load == 2
if z.Support == 1
Beam.y1 = (o*x.^2/24*E*I)*(x.^2+6*L^2-4*L*x);
else % x.Support == 2
Beam.y1 = (o*x.^2/24*E*I)*((L^3-2*L*x.^2)+x.^3);

Accepted Answer

Walter Roberson
Walter Roberson on 30 Nov 2012
Several parts of your code have expressions of the general form
f(x) * g(x)
where x is a row vector and f and g transform row vectors to row vectors. Therefore the multiplication you are requesting by the "*" operator is matrix multiplication between two row vectors. Matrix multiplication requires columns to match with rows, not rows to match with rows.
What you probably want is the .* operator
f(x) .* g(x)
which does element-by-element multiplication.

More Answers (1)

Lawson Hoover
Lawson Hoover on 30 Nov 2012
Thank You! The code is now working perfectly fine.


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