How can i do apply operator componentwice in any vector in N dimensional space? Mat lab code for any vector in N dimension

Here is my vector in 100-dimension.

v=
-20
9
-50
90
60
8
16
50
-43
.
.
.
-15

I want to implement operator for each component: i.e if the component is less than -10, take 0. the component is less than between -10 and 10, take 1, the component is greater than or equal to than 10, take 2.

Operating componentwise using this and putting all together as one vector is my problem.

for the above vector, the resulting vector will be

v=
 0
 1
  0
  2
  2
1
2
2
0
  .
  .
  .
  0

How can I code this for an arbitrary vector in N-dimensional vector? in 1000 dimensional, in 200000 dimensional?

Answer 1

[Star Strider]

Try this:

f = @(x) 0.*(x <= -10) + 1.*((x > -10) & (x < 10)) + 2.*(x >= 10);  % Anonymous Function

v = randi([-99 99], 20, 1);                                         % Create Vector
Result = [v f(v)]                                                   % Vector & Classification

Result =
    14     2
    69     2
   -93     0
    28     2
    57     2
   -86     0
   -35     0
     2     1
   -42     0
    -3     1
    14     2
   -73     0
   -43     0
   -91     0
    25     2
    73     2
    -9     1
   -34     0
    39     2
   -29     0

Note that this function is vectorised, so it also works for matrices.

[Dinoma Degefa]

thanks Sir. perfectly working

[Star Strider]

My pleasure.

If my Answer helped you solve your problem, please Accept it!

Answer 2

[Stephen23]

Simpler:

>> v = [-20;9;-50;90;60;8;16;50;-43]
v =
  -20
    9
  -50
   90
   60
    8
   16
   50
  -43
>> w = (v>=-10)+(v>=10)
w =
   0
   1
   0
   2
   2
   1
   2
   2
   0

Answer 3

[Walter Roberson]

discretize(v,[-inf,-10, 10,inf]) - 1

or

[~,bin] = histc(v,[-inf,-10, 10,inf]);
bin - 1

[Steven Lord]

When you call discretize, you can specify the values that should be stored in the output instead of the bin number using the third input.

v = 20*randn(10, 1);
v2 = discretize(v, [-Inf, -10, 10, Inf], [73 42 -999]);
[v, v2]

Elements in v between -Inf and -10 will have 73 in the corresponding element of v2 and similarly for the second and third bins.

[Walter Roberson]

Thanks, Steven. That would give us

discretize(v,[-inf -10 10 inf],[0 1 2])

which might be clearer to read.