Is there a way to change a vector range by condition?

Hallo,

i use a simple example for my problem:

i have a vector

x=[-10:10];
x=x';

Now i want to change values of the range 5:15 which are positive. i tried something like this:

x(5:15 & x>0,1)=100
x( (5:15) & (x>0) ,1)=100
x(5:15,1)&x>0=100
x(x(5:15)<0,1)=100

nothing seems to work. pls help.

Answer 1

[Andrei Bobrov]

x=(-10:10)';

z = x(5:15);
z(z>0) = 100;
x(5:15) = z;

or

x=(-10:10)';

b = false(size(x));
b(5:15) = true;
x(b & x > 0) = 100;

or in one row

x(intersect(find(x>0),5:15)) = 100;

[maxmathlab]

thanks. not a one row command but this is what I needed.

Answer 2

[KSSV]

If you want to change values at known indices use:

x(5:15)=100;

If you want to change values according to the values of x use:

x(x>1)=100;
x(x>1 & x<2)=100;

[maxmathlab]

i know matlab this far. but how do i combind it?

for e.g.: if i want to change my vector x from x(5) to x(15) but also only negativ values, what would the command look like?