A line in my code is being skipped

A line in a code I found in Matlab Documentation is being skipped. The code worked for others but not for me. you can find the code at:

https://www.mathworks.com/matlabcentral/fileexchange/34156-cantilever-beam-calculations?s_tid=srchtitle

Here is the code:

function Cbeam(~)

% Cbeam.m Cantilever Beam calculations

% HELP: This script computes mode shapes and corresponding natural

% frequencies of the cantilever beam by a user specified mechanical

% properties and geometry size of the C-beam.

% Prepare the followings:

% - Material properties of the beam, viz. density (Ro), Young's modulus (E)

% - Specify a cross section of the beam, viz. square,rectangular, circular

% - Geometry parameters of the beam, viz. Length, width, thickness

% -

%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% by Sulaymon L. ESHKABILOV, Ph.D

% October, 2011

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

clear all;

clc;

close all;

display('What is the X-section of the beam to be computed ?')

disp('If circle, enter 1. If square, enter 2')

disp('If rectangle, enter 3')

disp('If your beam"s X-section is not listed here, enter 4')

disp('To see example #1, hit ENTER or enter 0')

disp('To see example #2, enter 5')

CS=input(' Enter your choice: ');

if isempty(CS) || CS==0

disp('Example #1. Rectangular X-section Aluminum beam')

disp('Length=0.321 [m], Width=0.05 [m], Thickness=0.006 [m];')

disp('E=69.9*1e9 [Pa]; Ro=2770 [kg/m^3]')

L=.321;

W=.05;

Th=.006;

A=W*Th;

V=L*W*Th;

Ix=(1/12)*W*Th^3;

Iy=(1/12)*(W^3)*Th;

E=69.90e+9;

Ro=2770;

elseif CS==1

R=input('Enter Radius of the X-section: ');

L=input('Enter Length: ');

Ix=(1/4)*pi*R^4;

Iy=Ix;

A=pi*R^2;

disp('Material properties of the beam')

display('Do you know your beam"s material properties, viz. Young"s modulus and density ?')

YA=input('Enter 1, if you do; enter 0, if you don"t ');

if YA==1

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

else

display('Steel: E=2.1e+11 [Pa]; Ro=7850 [Kg/m^3]')

display('Copper: E=1.2e+11 [Pa]; Ro=8933 [Kg/m^3]')

display('Aluminum: E=0.69e+11 [Pa]; Ro=2700 [Kg/m^3]')

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

end

elseif CS==2

W=input('Enter Width of the X-section in [m]: ');

L=input('Enter Length in [m]: ');

Ix=(1/12)*W^4;

A=W^2;

disp('Material properties of the beam');

disp('Do you know your beam"s material properties, viz. Young"s modulus and density ?')

YA=input('Enter 1, if you do; enter 0, if you don"t: ');

if YA==1

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

else

display('Steel: E=2.1e+11 [Pa]; Ro=7850 [Kg/m^3]')

display('Copper: E=1.2e+11 [Pa]; Ro=8933 [Kg/m^3]')

display('Aluminum: E=0.69e+11 [Pa]; Ro=2700 [Kg/m^3]')

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

end

elseif CS==3

W=input('Enter Width of the X-section in [m]: ');

Th=input('Enter Thickness of the X-section in [m]:');

L=input('Enter Length in [m]: ');

Ix=(1/12)*W*Th^3;

Iy=(1/12)*(W^3)*Th;

A=W*Th;

disp('Material properties of the beam')

disp('Do you know your beam"s material properties, viz. Young"s modulus and density ?')

YA=input('Enter 1, if you do; enter 0, if you don"t: ');

if YA==1

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

else

display('Steel: E=2.1e+11 [Pa]; Ro=7850 [Kg/m^3] ')

display('Copper: E=1.2e+11 [Pa]; Ro=8933 [Kg/m^3] ')

display('Aluminum: E=0.69e+11 [Pa]; Ro=2700 [Kg/m^3] ')

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

end

elseif CS==4

display('Note: you need to compute Ix (area moment of inertia along x axis) and X-sectional area')

L=input('Enter Lengthin [m]: ');

Ix=('Enter Ix in [m^4]: ');

A=('Enter X-sectional area in [m^2]: ');

disp('Material proprties of the beam')

disp('Do you know your beam"s material properties, viz. Young"s modulus and density ?')

YA=input('Enter 1, if you do; enter 0, if you don"t ');

if YA==1

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

else

display('Steel: E=2.1e+11 Pa; Ro=7850 Kg/m^3 ')

display('Copper: E=1.2e+11 Pa; Ro=8933 Kg/m^3 ')

display('Aluminum: E=0.69e+11 Pa; Ro=2700 Kg/m^3 ')

E=input('Enter Young"s modulus in [Pa]: ');

Ro=input('Enter material density in [kg/m^3]: ');

end

elseif CS==5

display('Example #2')

display('This is a rectangular X-sectional steel beam ')

display('Length=0.45 m; Width=0.04 m; Thickness=0.003 m;')

L=.45; W=.04; Th=.003;

A=W*Th;

Ix=(1/12)*W*Th^3;

E=2.1*1e11; Ro=7.85*1e3;

else

F=warndlg('It is not clear what your choice of X-section of a beam is. Re-run the script and enter your beam"s X-section !!!','!! Warning !!');

waitfor(F)

display('Type in:>> Cbeam')

pause(3)

return

end

display('How many modes and mode shapes would you like to evaluate ?')

HMMS=input('Enter the number of modes and mode shapes to computed: ');

if HMMS>=7

disp(' ')

warning('NOTE: Up to 6 mode shapes (plots) are displayed via the script. Yet, using evaluated data (Xnx) of the script, more mode shapes can be plotted');

disp(' ')

end

Nm=3*HMMS;

jj=1;

while jj<=Nm;

betaNL(jj)=fzero(@(betaNL)cosh(betaNL)*cos(betaNL)+1,[jj jj+3]);

jj=jj+3;

end

index=(betaNL~=0);

betaNLall=(betaNL(index))';

%fprintf('betaNL value is %2.3f\n', betaNLall);

betaN=(betaNLall/L)';

k=1;

wn=ones(1,length(betaN));

fn=ones(1,length(wn));

while k<=length(betaN);

wn(k)=betaN(k)^2*sqrt((E*Ix)/(Ro*A));

fn(k)=wn(k)/(2*pi);

fprintf('Mode shape # %2f corresponds to nat. freq (fn): %3.3f\n', k, fn(k) );

k=k+1;

end

x=linspace(0, L, 180);

xl=x./L;

sigmaN=zeros(1, HMMS);

for ii=1:HMMS;

sigmaN(ii)=(sinh(betaN(ii)*L)-sin(betaN(ii)*L))/(cosh(betaN(ii)*L)+cos(betaN(ii)*L));

end

Tc='(cosh(betaN(ii).*x(jj))-cos(betaN(ii).*x(jj)))-sigmaN(ii).*(sinh(betaN(ii).*x(jj))-sin(betaN(ii)*x(jj)))';

Xnx=zeros(length(betaN),length(x));

for ii=1:length(betaN)

for jj=1:length(x)

Xnx(ii,jj)=eval(Tc);

end

end

% Plot mode shapes;

MMS=HMMS;

if MMS==1

plot(xl,Xnx(1,:), 'b-')

title('Mode shape of the Cantilever beam')

legend('Mode #1', 0); xlabel('x/L'); ylabel('Mode shape X_n(x)'); grid

hold off

elseif MMS==2

plot(xl,Xnx(1,:), 'b-'); hold on

plot(xl,Xnx(2,:), 'r-');grid

title('Mode shapes of the Cantilever beam')

legend('Mode #1', 'Mode #2', 0)

xlabel('x/L'); ylabel('Mode shape X_n(x)')

hold off;

elseif MMS==3

plot(xl,Xnx(1,:), 'b-'); hold on

plot(xl,Xnx(2,:), 'r-')

plot(xl,Xnx(3,:), 'm-');grid

title('Mode shapes of the Cantilever beam')

legend('Mode #1', 'Mode #2', 'Mode #3', 0)

xlabel('x/L'); ylabel('Mode shape X_n(x)')

hold off;

elseif MMS==4

plot(xl,Xnx(1,:), 'b-'); hold on

plot(xl,Xnx(2,:), 'r-')

plot(xl,Xnx(3,:), 'm-')

plot(xl,Xnx(4,:), 'c-'); grid

title('Mode shapes of the Cantilever beam')

legend('Mode #1', 'Mode #2', 'Mode #3', 'Mode #4', 0)

xlabel('x/L'); ylabel('Mode shape X_n(x)')

hold off;

elseif MMS==5

plot(xl,Xnx(1,:), 'b-'); hold on

plot(xl,Xnx(2,:), 'r-')

plot(xl,Xnx(3,:), 'm-')

plot(xl,Xnx(4,:), 'g-')

plot(xl,Xnx(5,:), 'k-')

grid

title('Mode shapes of the Cantilever beam')

legend('Mode #1', 'Mode #2', 'Mode #3', 'Mode #4', 'Mode #5', 0)

xlabel('x/L'); ylabel('Mode shape X_n(x)')

hold off

elseif MMS>=6

plot(xl,Xnx(1,:), 'b-'); hold on

plot(xl,Xnx(2,:), 'r-')

plot(xl,Xnx(3,:), 'm-')

plot(xl,Xnx(4,:), 'g-')

plot(xl,Xnx(5,:), 'k-')

plot(xl,Xnx(6,:), 'c-')

grid

title('Mode shapes of the Cantilever beam')

legend('Mode #1', 'Mode #2', 'Mode #3', 'Mode #4', 'Mode #5','Mode #6', 0)

xlabel('x/L'); ylabel('Mode shape X_n(x)')

hold off

end

end

my problem is that when I enter option 4 for the firsty inquiry, line 101 is being skipped. the code worked for other people in different PC's but not for mine/ Please help me resolve this issue

[John D'Errico]

Seriously, how do we know what line 101 is? If you want help, then make it easy to get help. Give us a hint, instead of forcing us to paste this mess of code into the editor, and then hope that the line numbered 101 is the same as it was on your computer. And, remember, we cannot run this code, without knowing ALL of the parameters you entered in.

So make it easy to get help. Provide sufficient information that someone can look at the code right here, so we can see the reason for your problem directly.

Answer 1

[Image Analyst]

You need to learn how to debug the code by stepping through it line by line. You won't get very far using MATLAB if you can't do that. Debugging via MATLAB Answers is a very slow and unreliable process. You will need to learn how to do it. Trust me, it's not hard. See this link:

Debugging in MATLAB | Doug's MATLAB Video Tutorials