# Matlab parachute

Discussion in 'Programmer's Corner' started by Bigcountry, Aug 30, 2014.

1. ### Bigcountry Thread Starter Active Member

Jul 4, 2008
71
0
I have to create a function then execute it in the command window.

I need to find "c" by graphic means.

I am starting at something like this :

a = fnval(dummy,c)
fnval(c,dummy)
fnval(...,'l')

The program works if I plug in some value for "c" in the equation. I just need to figure out how to get it to use an infinite amount of values.

thanks for any help.

function dummy=parachute(c)
m=68;
g=9.81;
t=10;
v=45;
dummy=-v+(g*m./c)*(1-exp(-c/m)*t);
fplot('parachute',[0,20])

grid on

xlabel('c')

ylabel('f(c)')

end

2. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,377
494
Why don't you define c?
c=0:0.1:10000;

The first value of c is zero. Then c is incremented by 0.1, so new c is 0.1. Then c is incremented again, new c is 0.2. And so on until you reach 10000. You graph will have 100,000 points.

Hmm, I guess you don't want to divide by zero. Then you can do this:
c=0.1:0.1:10000;

3. ### Bigcountry Thread Starter Active Member

Jul 4, 2008
71
0
Thank you! I always have a hard time getting started. Now I have to figure out how to create a function to find "c" at 10 seconds on the graph. This is a good start.

4. ### Bigcountry Thread Starter Active Member

Jul 4, 2008
71
0
Now I am getting an error message.

Maximum recursion limit
of 500 reached. Use
set(0,'RecursionLimit',N)
to change the limit. Be
aware that exceeding