Array indexing and processing

Hi there,

I was wondering if someone could help explain what the following line of matlab code is doing -

R = H(npt-1:-1:2);

Where H is a vector (or 1 * 513 matrix) of complex numbers.

Thanks for any tips

Answer 1

[Star Strider]

That line assigns to ‘R’ values of ‘H’ using index references starting at ‘npt-1’, decrementing by 1 to ‘H(2)’.

For instance:

H = [1:10];
npt = 10;
R = H(npt-1:-1:2)

‘R’ is assigned:

R =

       9     8     7     6     5     4     3     2

Answer 2

[Gilbert S]

Perfect, thank you! My Matlab is rusty, so coming from a C background, things like this can slow me down..!

Thanks for your help..

[Star Strider]

My pleasure!