i'm tryin to plot a relationship between 2 variables on a graph within matlab. i have a large expression i'm tryin to put in that includes 5 values, 4 known and the other that will be a range. i keep getting a numerical answer for the large expression which is not supposed to happen. anyone know why that is happening?

this is my coding:

a=0.1
m=2000
c=1.2e5
k=4e6
w=(-50:.1:50);
z=a*[(k.^2+(c*w).^2)/((k-m*w.^2).^2+(c*w).^2)]^.5;

z = 0.1189

when i evaluate z i get that numerical answer and i'm not supposed to because it is supposed to be a graphical comparison of z versus changing w.

6/9/2006 11:12:49 PM

be sure that you are using []'s for a vector, and ()'s for parenthetical multiplication...

try..

a=0.1
m=2000
c=1.2e5
k=4e6
w=[-50:.1:50];
z=a*((k.^2+(c*w).^2)/((k-m*w.^2).^2+(c*w).^2))^.5;

[Edited on June 9, 2006 at 11:42 PM. Reason : nmnm]

6/9/2006 11:38:31 PM

.

[Edited on June 9, 2006 at 11:40 PM. Reason : ^ beat me to it]

6/9/2006 11:39:51 PM

oh, use ./ for your division as well.

6/9/2006 11:45:18 PM

that was it! the ./ was screwin me up


thanks so much

[Edited on June 9, 2006 at 11:48 PM. Reason : .]

6/9/2006 11:46:50 PM

i'm doing some work with Gibb's Phenomenon and square wave stuff and i've gotten this:



how do i zoom out so i can see the entirety of the square wave? that view is just a closeup of that 1 section but i need to see the whole thing. and yes, i've tried the zoom out tool within the plot window but wont let me go any further.

[Edited on June 11, 2006 at 6:06 PM. Reason : .]

6/11/2006 6:05:57 PM

bttt for square wave question

6/11/2006 7:43:02 PM

doesn't really look like a square wave....but anyways, the gibbs phenomenon presents itself when you add many, many terms to the fourier series. for the square wave, the fourier coefficients are sinc's.

for a very cursory answer to your question, if you want to "zoom out", you need to make your dependant variable longer in length. you have it running from 0 to 60 ... increase the length to 120 or whatever.

6/11/2006 7:54:56 PM