Case instead of if-then?

Hi,

I have:

solveload=[0 0 0 'x' 'y' 'z'];

And need to determine only the position of the x, the y, and the z, when they could be anywhere in the vector, with 0's elsewhere. I'm finding I need a bunch of if-then's. It must be easier?

Thanks in advance :)

Dave

Answer 1

[Star Strider]

There seem to be missing information.

What characterises ‘x’, ‘y’, and ‘z’?

What makes them so difficult to find? Range? Real/Complex? Something else?

[David Pesetsky]

To find their positions, I need 6 if-then's for "x", 6 for 'y', and 6 for 'z'. Just seems excessive...

[Star Strider]

How are they organised in the vector?

How can you determine which is which?

[David Pesetsky]

They can be arranged any way. x 0 0 y z 0 for example.

This didn't work because when it found the x, it just stopped:

 if solveload(1) == 'x'
  x(k) =  zz(1)*LRF;
 elseif solveload(1) == 'y'
  y(k) =  zz(1)*LRF;
 elseif solveload(1) == 'z'
  z(k) =  zz(1)*LRF;
 elseif solveload(2) == 'x'
  x(k) =  zz(2)*LRF;
 elseif solveload(2) == 'y'
  y(k) =  zz(2)*LRF;
 elseif solveload(2) == 'z'
  z(k) =  zz(2)*LRF;
 elseif solveload(3) == 'x'
  x(k) =  zz(3)*LRF;
 elseif solveload(3) == 'y'
  y(k) =  zz(3)*LRF;
 elseif solveload(3) == 'z'
  z(k) =  zz(3)*LRF;
 elseif solveload(4) == 'x'
  x(k) =  zz(4)*LRF;
 elseif solveload(4) == 'y'
  y(k) =  zz(4)*LRF;
 elseif solveload(4) == 'z'
  z(k) =  zz(4)*LRF;
 elseif solveload(5) == 'x'
  x(k) =  zz(5)*LRF;
 elseif solveload(5) == 'y'
  y(k) =  zz(5)*LRF;
 elseif solveload(5) == 'z'
  z(k) =  zz(5)*LRF;
 elseif solveload(6) == 'x'
  x(k) =  zz(6)*LRF;
 elseif solveload(6) == 'y'
  y(k) =  zz(6)*LRF;
 else
  z(k) =  zz(6)*LRF;
 end

I'll need to if-then from 1-6, once each for x, y, and z for this to work.

[Star Strider]

Do they always occur in ‘(x,y,z)’ order, and are zero elsewhere?

[David Pesetsky]

any order of x and y and z, with 0's everywhere else.

0 z x 0 0 y is possible.

Maybe there's a match function, or index, or split....

[David Pesetsky]

This works:

find(ismember(solveload,'y')==1)

http://www.mathworks.com/matlabcentral/answers/49819-excel-lookup-or-match-function-in-matlab

[Star Strider]

I’m glad you solved it, because I have no idea how to differentiate x, y, and z from your description.