[Q] Programming & "Not Floating Point Number" Error
- Subject: [mg3133] [Q] Programming & "Not Floating Point Number" Error
- From: ntd at cs.duke.edu (Noel T. Doromal)
- Date: 7 Feb 1996 09:07:56 -0600
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: Duke University
- Sender: daemon at wri.com
Hello out there! This is my first time on this group, so I apologize for
breaking any netiquette rules.
I have a Mma question that I hope someone out there can help me with. I
recently started using Mma for a class and have had a hard time
"programming" with it. Here is the script/program that i wrote:
--
epsilon = .01
gamma = 7
dt = .125
stim = 0
y0 = -.5
w0 = 0.0
For[i=0, i<50, i++,
f = y0 * (1 - y0 *y0);
v = y0 + (f - w0) * dt;
w = w0 +(epsilon*(gamma*y0 - w0)) * dt;
vee[i] = v;
doubleu[i] = w;
y0 = v;
w0 = w;
]
ListPlot[{vee,doubleu}]
---
First question: Are there examples of Mma programs out there that are
longer than a line or two? (Or was mathematica not really made for
programming?) I bought the book and can't find any in there. (It
describes the control structures: do, if, for... but then gives one line
examples only)
Second: In the script above I'm essentially calculating a bunch of points
that I want to plot (V vs. W - I had to use "vee" and "doubleu" to get it
to work). The only way I could figure to do it was to store the numbers
in a list and then use ListPlot[] but I can't get it right. I keep
getting:
--
Graphics::gptn:
Coordinate vee in {1, vee} is not a floating-point number.
Graphics::gptn:
Coordinate doubleu in {2, doubleu} is not a floating-point number.
--
What am I doing wrong?
Thanks for the help,
Noel