How to rectify this error ?

Hello

Please how to rectify this error ?

Error in trapz (line 72)

if ~isempty(perm), z = ipermute(z,perm); end

Error in Variable_sec (line 194)

sigma_r(:,kmj) = trapz(x,m* Mode_shape(:,kmj));

The program is :

% width
b0 = 0.01;
x = linspace(0,L,100);
ratio = 1;
b  = b0*ratio + (1/L)*b0*(1-ratio)*(L-x);
% masse
m_const = (rhos * hs + rhop* hp);  
m = b * m_const;
% Layer thickness (hs = substrate, hp = piezo)
hs = 0.0005;
hp = 0.0001;
% Density of piezo
rhop = 7800;
% Density of substrate 
rhos = 8700 ;
% Setion lengths 
L = 0.035;

% lambda
f=  @(lambda) 1+(cos(lambda)*cosh(lambda)) ;
for i=1:nlambda
 lambda(i) = fzero(f, (pi/2)+pi*(i-1));
end

for km =1:nlambda
    psi(km)= ( -cos (lambda(km))- cosh(lambda(km)) )/ ( -sin(lambda(km))+ sinh(lambda(km)) ) ;
    x = linspace(0,L,100);
    Mode_shape (:,km) = sin ( (lambda(km)/L)*x)- sinh( (lambda(km)/L)*x)+ psi(km) *( cos( (lambda(km)/L)*x) - cosh( (lambda(km)/L)*x));
        end

%Modal forcing
for kmj=1:nlambda
    sigma_r(:,kmj) = trapz(x,m* Mode_shape(:,kmj));
end

[madhan ravi]

what's nlamda?

[Mallouli Marwa]

nlambda=11;

Answer 1

[madhan ravi]

L = 0.035;
hs = 0.0005;
hp = 0.0001;
rhop = 7800;
rhos = 8700 ;
b0 = 0.01;
x = linspace(0,L,100);
ratio = 1;
nlambda=11;
b  = b0*ratio + (1/L)*b0*(1-ratio)*(L-x);
m_const = (rhos * hs + rhop* hp);  
m = b * m_const;
f=  @(lambda) 1+(cos(lambda)*cosh(lambda)) ;
lamda=zeros(1,nlambda); % preallocate
for i=1:nlambda
 lambda(i) = fzero(f, (pi/2)+pi*(i-1));
end
 x = linspace(0,L,100);
 psi=zeros(1,nlambda);
 sigma_r=zeros(100,nlambda);
for km =1:nlambda
    psi(km)= ( -cos (lambda(km))- cosh(lambda(km)) )/ ( -sin(lambda(km))+ sinh(lambda(km)) ) ;
    Mode_shape = sin ( (lambda(km)/L)*x)- sinh( (lambda(km)/L)*x)+ psi(km) *( cos( (lambda(km)/L)*x) - cosh( (lambda(km)/L)*x));
    sigma_r(:,km) = trapz(x,m.* Mode_shape.');
end

[madhan ravi]

See edited answer

[Mallouli Marwa]

The mode_shape dimension must be 100*11

So it must be still mode_shape(:,km)

Please help me

[madhan ravi]

So see Star Striders answer .

[Mallouli Marwa]

His program runs with error.

Your try is good but if you can change the dimension of mode shape

[madhan ravi]

See edited answer.

[Mallouli Marwa]

Thanks a lot.

[madhan ravi]

Anytime :)