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View Full Version : whats wrong with this matlab code?


ranger
Feb22-07, 05:32 PM
I have a very simply matlab code. When I try go run it, I get no graph and switching over to the matlab command line, I see:
ans =

char

Here is the code:

t = linspace(0,60);
v = 3.22;

for q_0 = [0:1:2007];
q = q_0*exp(v*t);
plot(t,q)
hold on
end

It looks just fine to me.

Any feedback would be great.

chroot
Feb22-07, 05:58 PM
It runs fine in MATLAB R2006b on my computer.

Perhaps try removing the semicolon at the end of "for q_0 = [0:1:2007];"

- Warren

ranger
Feb22-07, 06:06 PM
I still get no luck. I can run other m-files from the same directory with no problems. Does it say anything on the matlab command line when you run it?

doodle
Feb22-07, 09:05 PM
I have copied-and-pasted the script on the Matlab (R11.1) command prompt and a figure appears. Nothing appears in the command line though.

How did you try to run the script?

Dr Transport
Feb22-07, 09:31 PM
It looks to me to be plotting every point in a separate graph,, try writing to an array and plot after the loop is complete. I;ll try at work tommorow where I have Matlab R2006B.

ranger
Feb22-07, 10:33 PM
I have copied-and-pasted the script on the Matlab (R11.1) command prompt and a figure appears. Nothing appears in the command line though.

How did you try to run the script?

I tried to run it from the m-file editor screen. The usual Debug>Run. I also even tried to get it from the command line, but I still get ans = char as an output.

It looks to me to be plotting every point in a separate graph,, try writing to an array and plot after the loop is complete. I;ll try at work tommorow where I have Matlab R2006B.
I dont think its separate graphs. Its done on one graph but the "hold on" command allows me to plot different values for q_0 on the same graph.


Its is possible for anyone to post a screenshot of the graph? btw, I'm using R14.

doodle
Feb23-07, 12:14 AM
Its is possible for anyone to post a screenshot of the graph? btw, I'm using R14.

Here's a screenshot...

ranger
Feb23-07, 09:51 AM
Thanks doodle. It seems I have to do a little tweaking of my domain, but its what I expected it to be.

ranger
Mar7-07, 07:44 PM
It turns out I was getting this error becuase the name of the M-file had a white space. Beats me...