Looks like it doesn't like your plot(time,farray(m,:)’gc')

I'd guess a missing comma.

Cheers

Greg Locock

putting the comma in, just changes the error say: "??? Error: File: C:\MATLAB7\work\square.m Line: 16 Column: 27
Missing variable or function." so that doesn't seem to change the problem all that much

square.m

clf
%trying to find a square wave
time = [0:0.01:10];
T=10;
omega=2*pi*1/T;
fsummation=0
k=1;
gc = ['b','c', 'm', 'k', 'y','g', 'r', 'b'];

for ndx=[1:2:19],
farray(k,:) = fsum(time, omega, ndx);
subplot(10,2,ndx)
    for m=1:k,
    hold on
    gc(mod(k,8)+1)
    plot(time,farray(m,:),’gc')
    end
fsummation = fsummation + farray(k,:)
subplot(10,2,ndx+1)
plot(time, fsummation’r’)
k=k+1;
end
gtext('Archie Brentano SN')

figure
pwrspec(fsummation, 1000,100)
gtext(‘other name’)

Well, the advantage of a modular language is that you can go into debug mode. Write some routines that test each subroutine by itself. Comment out the parts of the code that are not essential to its function, such as plot...

Incidentally I can't say I like the look of gc(mod...

either but that may be you doing something fancy to an array of strings, not the sort of thing I do.

Cheers

Greg Locock

There are some errors spread out through your code

1. You use ’ instead of ' several times.
2. The fsum function has a VB-like syntax that doesn't work in matlab.

   CODE

   function out = fsum(time, omega, ndx)
   %fsummation
   out = 4/pi*1/ndx * sin(ndx*omega*time);
   is much better.
3. As Greg said, gc(mod(k,8)+1) is wrong. Something like this is better.

   CODE

   color=gc(mod(k,8)+1);
   plot(time,farray(m,:),color)

The pwrspec.m doesn't seem to have any errors.

This was what I found when giving it a quick look, there might be more problems.

well i finally got it to work. here is the code if anyone wants to know:

square.m

clf
%trying to find a square wave
time = [0:0.01:10];%gives the increments of measuring for time
T=10;%the amount of time it takes to run through the run
omega=2*pi*1/T;
fsummation=0;%starting parameter for the right graph
k=1;%starting inner and outer variable
gc = [ 'k', 'b', 'g', 'r', 'c', 'm', 'y'];%color array
gh = 1;%labels the title of Square wave
gp = 1;%labels the title of partial series
u = [0, 10, -1.25, 1.25]%limits the axis of the graphs
pr = [0, 6, 0, 60000]
for ndx=[1:2:19],%this is the index which tells the script to run on the odd numbers
    farray(k,:) = fsum(time, omega, ndx);
    subplot(10,2,ndx);
     
    for m=1:k;   
        color=gc(mod(m,7)+1);
        plot(time, farray(m,:), color);
        hold on

        if (gp==1)
            title('Partial series: 1,3,5,7,9,11,13,15,17,19')
        end
        gp = gp + 1
    
  
    axis(u)
   
        if (ndx==19)
            xlabel('sec')
        end
   
   grid on
   end
   
fsummation = fsummation + farray(k,:);
subplot(10,2,ndx+1);
plot(time, fsummation, 'r');
k=k+1;
    axis(u)
   if (ndx==19)
   
       
    xlabel('sec')
   end
    grid on
   
   if (gh == 1)
   title('Square wave synthesis')
   end
   gh = gh + 1
    
end
gtext('Archie Brentano SN: 930-584-308 ECE111 Fall 2004 ')



figure
pwrspec(fsummation, 1000,100)
axis(pr);
gtext('Archie Brentano SN: 930584-308 ECE111 Fall 2004')

fsum.m

function out = fsum(time, omega, ndx)
%fsummation
%time is a time-axis vector
%rfreq is the radian frequency
%idx is the square wave synthesis degree index
%fsum will calculate a term of a series of sine waves that will approach a square wave
out = 4/pi*1/ndx * sin(ndx*omega*time)

pwrspec.m

function pwrspec(signal, N, srate)
% pwrspec(signal, N, srate)
% pwrspec computes the power spectrum of a signal and creates a plot
% signal = vector containing signal values
% N = desired length of vector, normally obtained from "length()" function
% srate = sampling rate used to calculate signal, typically twice the value of
%         highest frequency

P = fft(signal,N);
n = length(P);
plen = floor(n/2);
power = abs(P(1:plen)).^2;
nyquist = 1/2 * srate;
freq = (1:plen)/(plen)*nyquist;

stem(freq,power)
title('Power spectrum of signal stream')
xlabel('frequency (Hz)')
ylabel('signal intensity')
grid

thank you.