# Wrong equastion of XY dependence

1 view (last 30 days)
Pavol Namer on 7 Aug 2014
Commented: Pavol Namer on 7 Aug 2014
Hi I try to solve following problem.
I try to type following equastion of XY dependence:
x= [-5,15]
a= 1
b= 12
c= 2.4
r= 1
y= -1*(a-b*(((x)-r)).^4).*(exp(-1*c*((x)-r).^2))
figure
plot (x,y)
it should be this equation:
And it should have this shape of XY dependence
But it give me the wrong shape (like linear XY dependence).
Can anybody advise, where the mistake i?
Thank you
P.

Mischa Kim on 7 Aug 2014
Edited: Mischa Kim on 7 Aug 2014
Use,
x = -5:0.1:15; % create a vector x, element spacing: 0.1
a = 1;
b = 12;
c = 2.4;
r = 1;
y = -1*(a-b*(((x)-r)).^4).*(exp(-1*c*((x)-r).^2));
figure
plot(x,y)
The only difference is in the first line. In your code you evaluate y only twice, at x = -5 and at x = 15.
Pavol Namer on 7 Aug 2014
Oh my got :) Thanks a lot, I am totaly stupid guy :))

David Sanchez on 7 Aug 2014
x= -5:.01:15; % array of 2001 elements, your definition were a mere 2 element array
a= 1;
b= 12;
c= 2.4;
r= 1;
y= -1*(a-b*(((x)-r)).^4).*(exp(-1*c*((x)-r).^2));
figure
plot (x,y)