Error using * Inner matrix dimensions must agree.

Okay so I' trying put in the following commands.

%Constants%

hbar = 1.055e-34;   %J s  
c = 2.998e8;        %m/s    Speed of light
eps = 8.854e-12;     %C^2/N/m^2  permitivity of free space

%system parameters%

W = 20e-6;          %m          Beam width
l = 300e-6;         %m          Beam length
h = 2e-6;           %m          Beam thickness
rho = 2.33e3;       %kg/m^3             Material density (silicon)
E = 169e9;          %Pa         Youngs modulous
g = 8e-6;           %m          Initial gap distance
Q = 350             %Quality factor
V = 16;              %V          AC peak voltage
A = W*h;            %m^2        Cross sectional area
I = W*h*h*h/12;     %m^4        Cross sectional intertia

wn = 3.51562; %s^-1       natural frequency

%%%Constants from modeshapes%%%

g011 = 0.7830;     % g011 = <1,phi_1>      
g111 = 1;           % g111 = <phi_1,phi_1> 
g211 = 1.4778;     % g211 = <phi_1^2, phi_1>
g311 = 2.3488;      % g311 = <phi_1^3, phi_1>

%This constant tracks effects of Casimer Effect
%alpha = (pi*pi*hbar*c*W*l^4)/(240*g^5*E*I); 
alpha = 0;

%This constant tracks effects of the Electrostatic Force
%delta =(eps*W*l^4)/(2*g^3*E*I)*V*V;
delta = .01;

%This constant tracks effects of Fringing Correction to Elec. Force
%f = 0.65*g/W;
f = 0.26;

%Dimensionless damping coeff.
%b0*l^2/g*sqrt(1/(rho*A*E*I));
%b = wn/Q
b = 0.001; 

C1 = delta*(1+f)/2;
C2 = delta*(2+f)/2;
C3 = delta*(3+f)/2;
C4 = delta*(4+f)/2;

gamma=0.001:0.0001:pi;

amp = 2.*g111.*wn.*b./C3./g211./sin(gamma)-sqrt((2.*g111.*wn.*b./C3./g211./sin(gamma)).^2 - 4.*C1.*g011./C3./g211);

Where exactly should I put the periods so I don't get that error.

[Nalini Vishnoi]

Please specify what are the values for b, alpha, delta, wn, g111 .

[Valeria Garcia]

oops! should have explained more. I already put them.

Answer 1

[Star Strider]

We know gamma is a vector, but nothing about whether the other variables are vectors or scalars. In the absence of that information, just vectorise the entire expression unless you know specific operations involve only scalars.

Also, highlighting your code and then using the [{}Code] button makes it easier to read.

[Valeria Garcia]

okay, done.

[Star Strider]

Did the complete vectorisation work, or are you still having problems?