View Single Post
frozenguy
frozenguy is offline
#1
Feb23-12, 01:54 AM
P: 190
Please help me with this.

I need to code into matlab a function that results in a matrix answer.

It is this:
phi(i,j)=atan((eta(j)-eta(i))/(zeta(j)-zeta(i)))*180/pi]

Here is my code so far:
for i=1:4;

N=4;

w(i)=(360/N)*(i-0.5);

x(i)=-cos(w(i)*pi/180);

y(i)=sin(w(i)*pi/180);

x(5)=x(1);

y(5)=y(1);

zeta(i)=0.5*(x(i)+x(i+1));

eta(i)=0.5*(y(i)+y(i+1));

theta(i)=atan2((y(i+1)-y(i)),(x(i+1)-x(i)))*180/pi;

s(i)=sqrt((x(i+1)-x(i))^2+(y(i+1)-y(i))^2);

if theta(i)<0;

theta(i)=theta(i)+360;

end
j=1:4;

phi(i)=[atan((eta(i:N)-eta(i:N))/(zeta(i:N)-zeta(i:N)))*180/pi];

end
See I need a 4X4 matrix for phi.

I only have four etas and four zetas. both i and j = 4. With some work I can get a 4x4 matrix but it isn't coded right. It gives me the same answers in rows. It should have a diagonal line of zero's from top left to bottom right because that is where i=j

And I need to be able to change N to 250 so it needs to be easy to write for large N's

Thank you for your help!
Phys.Org News Partner Science news on Phys.org
Review: With Galaxy S5, Samsung proves less can be more
Making graphene in your kitchen
Study casts doubt on climate benefit of biofuels from corn residue