CODEWITHSUNDEEP
matlabdecision-tree
spr1te
spr1te

Reputation: 89

Checking variety of a vector in matlab

I'm trying to check a vector in matlab. As example a vector has 3 different possibilites 0 1 and 2. Now i want to check how many of 0s 1s and 2s there are inside of this vector within matlab, so i can determine the best split choice for my decision tree. Maybe there is any easier way to do it?

best regards

Upvotes: 1

Views: 39

Answers (2)

Mohammadreza Khoshbin
Mohammadreza Khoshbin

Reputation: 329

Although I like Brendan's answer, I prefer the following code.

array = [1 2 1 0 3 1 1 4];
num_1 = numel( find(array==1) );

find gives you the indices of the values. You can also use ~=, < and >.

I suggest you adapt this to a function.

Upvotes: 1

Brendan Frick
Brendan Frick

Reputation: 1025

With vector == some_num, you return a binary array of locations of some_num in vector. With vector(binary_array) you return a subset of the array, indicated by '1's in binary_array.

Putting that together:

vec = [ 0 0 1 1 1 2 2 2 2 2];
num_0 = length(vec(vec==0)); % = 2
num_1 = length(vec(vec==1)); % = 3

...

Upvotes: 1

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