Matlab code for summation?

  • MATLAB
  • Thread starter tunk
  • Start date
  • #1
6
0

Main Question or Discussion Point

i need to write this into matlab

http://www.engin.umich.edu/class/bme456/ch10fitbiphasic/biphasfit19.gif [Broken]

which i have done here:

uj = (-sig/Ha)*(xj-(((2*h)/(pi^2))*((((-1)^n)/((n+1/2)^(1/2)))*sin((n+1/2)*((pi*xj)/h))*exp(((-Ha*ko)/(h^2))*((n+1/2)^2)*(pi^2)*t))));

how do i vary n, and get the equation to sum over n=0-3? and then again from n=0-100?
 
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Answers and Replies

  • #2
1,341
3
Call everything inside the summation f(n)

for i=1:4 %n from 0 to 3 case
y(i) = f(i-1)
end

sum(y);

for i=1:101 %n from 0 to 3 case
y(i) = f(i-1)
end

sum(y);

-----

Should work
 
  • #3
7
0
Call everything inside the summation f(n)

for i=1:4 %n from 0 to 3 case
y(i) = f(i-1)
end

sum(y);

for i=1:101 %n from 0 to 3 case
y(i) = f(i-1)
end

sum(y);

-----

Should work
I got the following error for the same equation, following your summation of f(n),
"??? Subscript indices must either be real positive integers or
logicals.

Error in ==> scriptrun at 16
f(n)=sum(((abs((-1).^n))/((n+1./2).^(2))));"




My code:

for i=1:3 %n from 0 to 2 case
f(n)=sum(((abs((-1).^n))/((n+1./2).^(2))));
y(i)=f(i-1);
end
sum(y);
uj = (-sig/Ha)*(xj-(((2*h)/(pi^2))*f(n)*sin((n+1/2)*((pi*xj)/h))*exp(((-Ha*ko)/(h^2))*((n+1/2)^2)*(pi^2)*t)));

Any advise?
 
  • #4
1,341
3
You're summing uj = (-sig/Ha)*(xj-(((2*h)/(pi^2))*f(n)*sin((n+1/2)*((pi*xj)/h))*exp(((-Ha*ko)/(h^2))*((n+1/2)^2)*(pi^2)*t))) that's what f(n) is. just calling that expression will give an error, I believe.
 

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