Create index vector from grouping variable based on a condition

Hey!

I have a table with x variables that very in sign from - to +. I want to create a third column t.count in a table that includes -1 index for every negative x value, 0 for 0 and +1 for the positive x-values. The only similar command that I know is grip2idx but it doesn't do what I need in this case. Is there a way to do it ithout a for-loop?

x = [0 0.5 0.6 1 -0.03 -0.6 -0.8 0 0]'
y = [1:1:length(x)]'
t = table
t.x = x
t.y = y

Answer 1

[KSSV]

x = [0 0.5 0.6 1 -0.03 -0.6 -0.8 0 0]' ;
y = zeros(size(x)) ; 
y(x<0) = -1 ;
y(x>0) = +1 ;

T = table(x,y)

T = 9×2 table
      x      y 
    _____    __

        0     0
      0.5     1
      0.6     1
        1     1
    -0.03    -1
     -0.6    -1
     -0.8    -1
        0     0
        0     0