View Single Post
frozenguy
#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
World's largest solar boat on Greek prehistoric mission
Google searches hold key to future market crashes
Mineral magic? Common mineral capable of making and breaking bonds