Question

Help with matlab

Answer 1

What help do you need?

Answer 2

http://www.mathworks.com/help/techdoc/index.html is always helpful. :)

Answer 3

\[f(x)=x (e^-x) \cos(2x)\]
write into matlab

Answer 4

I have try many times but still failed

Answer 5

http://www.mathworks.com/help/techdoc/learn_matlab/f3-27853.html

Answer 6

Are you STRICTLY REQUIRED to use matlab? There are far easier ways to plot functions.

Answer 7

I want to make a function with that equation. But I failed to execute it.

Answer 8

function y = f(x)
y = x * exp(-x) * cos(2*x)

try that

Answer 9

OK, I'll try

Answer 10

y=f(x)
??? Error using ==> power
Not enough input arguments.

Answer 11

iwan -- are you required to use Matlab?

Answer 12

f might be a protected function name. Try something else like foo. Hopefully you know how to use a function, but I'm 99% sure my code will work.

Answer 13

Although I echo mathteacher. I use R predominantly. It's much quicker to use imo.

Answer 14

You can define a function as

% example matlab function
function y= f(x)
y= x.*exp(-x).*cos(2*x);
and save it in a script as "y.m"

or you can just type in the line
y= x.*exp(-x).*cos(2*x);

Note that the dots e.g. .* is used so this expression will work with a vector of inputs.

Answer 15

the script name should be "f.m" as the function name is "f"

Answer 16

OK, I got it. Now how to plot it ?
for x[0.2pi]

Answer 17

I mean for x[0, 2pi]

Answer 18

x=0:0.1:2*pi;
y= f(x);
plot(x,y)

Answer 19

OK, thanks