Wrong equastion of XY dependence

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.

Answer 1

[Mischa Kim]

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]

Oh my got :) Thanks a lot, I am totaly stupid guy :))

Answer 2

[David Sanchez]

Instead of your definition of x, try the folowing one:

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)