I have extracted HOG features for male and female pictures, now, I'm trying to use the Leave-one-out-method to classify my data.
Due the standard way to write it in Matlab is:
[Train, Test] = crossvalind('LeaveMOut', N, M);
What I should write instead of N
and M
?
Also, should I write above code statement inside or outside a loop?
this is my code, where I have training folder for Male (80 images) and female (80 images), and another one for testing (10 random images).
for i = 1:10
[Train, Test] = crossvalind('LeaveMOut', N, 1);
SVMStruct = svmtrain(Training_Set (Train), train_label (Train));
Gender = svmclassify(SVMStruct, Test_Set_MF (Test));
end
Notes:
Training_Set
: an array consist of HOG features of training folder images.
Test_Set_MF
: an array consist of HOG features of test folder images.
N
: total number of images in training folder.
- SVM should detect which images are male and which are female.
I will focus on how to use crossvalind
for the leave-one-out-method.
I assume you want to select random sets inside a loop. N
is the length of your data vector. M
is the number of randomly selected observations in Test
. Respectively M
is the number of observations left out in Train
. This means you have to set N
to the length of your training-set. With M
you can specify how many values you want in your Test
-output, respectively you want to left out in your Train
-output.
Here is an example, selecting M=2
observations out of the dataset.
dataset = [1 2 3 4 5 6 7 8 9 10];
N = length(dataset);
M = 2;
for i = 1:5
[Train, Test] = crossvalind('LeaveMOut', N, M);
% do whatever you want with Train and Test
dataset(Test) % display the test-entries
end
This outputs: (this is generated randomly, so you won't have the same result)
ans =
1 9
ans =
6 8
ans =
7 10
ans =
4 5
ans =
4 7
As you have it in your code according to this post, you need to adjust it for a matrix of features:
Training_Set = rand(10,3); % 10 samples with 3 features each
N = size(Training_Set,1);
M = 2;
for i = 1:5
[Train, Test] = crossvalind('LeaveMOut', N, 2);
Training_Set(Train,:) % displays the data to train
end