# No graphs after plot command

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##### 2 Comments

Geoff Hayes
on 15 Feb 2015

Star Strider
on 15 Feb 2015

semiha’s ‘Answer’ moved here ...

a = 100;

m = 1000;

n = 1000;

h = a/m;

t1 = 100;

k = t1/n;

x = 0:h:a;

t = 0:k:t1;

D = -k;

w0 = zeros(1,m+1);

w = zeros(n+1, m+1);

A = zeros(m+1, m+1);

B = zeros(m+1, m+1);

for j = 1:m+1

w0(j) = (1-(5*(1-3*i))/((1+6*(x(j)^3))));

end

w(1,:) = w0;

for p=1:n

for j=1:m+1

A2 (j)= k*1*i;

A(j,j) = A2(j);

end

for j=1:m

A(j,j+1) = 1 - 1i*D*abs(w(p,j)).^2;

end

for j=1:m-1

A(j,j+2)=k*1*i;

end

A(m,m)=k*1*i;

A(m,1)= 1 - 1i*D*abs(w(p,j)).^2;

A(m,2)=k*1*i;

A(m-1,1)=k*1*i;

A(m-1,m)= 1 - 1i*D*abs(w(p,j)).^2;

A(m-1,m-1)=k*1*i;

r =(A)*w(p,1:m+1)';

w(p+1,1:m+1)=r';

end

plot3 ( x, t,(abs(w(n,:))) );

### Answers (1)

emehmetcik
on 15 Feb 2015

Your output variable "w" mostly consists of "nan" (not a number) values. Probably the result of zero divided by zero at some point.

Only the first few rows of "w" have no nan's.

##### 3 Comments

emehmetcik
on 15 Feb 2015

I'm not quite sure what the code does. But the problem seems to be that some values grow exponentially.

My recommendation is that you should re-check your code. The following commands can be useful as well:

dbstop if naninf

This will automatically put a debug point when a nan or inf value is encountered while the code is being executed.

dbclear all % To clear all debug points

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