Help extracting data from solution matrix

I have this simple code here,

if true
A=[1 0 0
  0 1i -2i
  0 -2i (3+2i)]
C=[-4.5
  6
  0]
B=[1i
  2i
  3i]
I=A\C
end

and it gives this answer,

if true 
I =

-4.5000 + 0.0000i
 5.5385 - 2.3077i
 2.7692 + 1.8462i
end

I'd like to apply sqrt((real)^2+(imaginary)^2) and atand(imaginary/real) to the solution vector. Actually, I'm only concerned with row 3 of the solution vector. How would I do that? Thanks for the help.

Answer 1

[Star Strider]

MATLAB has two functions that will do exactly what you want:

I = [-4.5000 + 0.0000i
     5.5385 - 2.3077i
     2.7692 + 1.8462i];

Amplitude = abs(I);             % Units: Original Units
Phase = angle(I);               % Units: Radians

[Brian Hoblin]

Great! that was exactly what I was looking for. Thank you!

[Star Strider]

As always, my pleasure!