How to combine features

I write a code that detect people in crowed and I tray to use SURF , MSERF and HOG Features my quistion how can i combine this features ???

points1 = detectSURFFeatures(grayI)

[feature, valid_points] = extractFeatures(grayI, points1);

[regions,dd] = detectMSERFeatures(grayI);

[features2, valid_points] = extractFeatures(grayI,regions);

[featureVector,hogVisualization] = extractHOGFeatures(grayI);

Answer 1

[Sai Bhargav Avula]

To get the combined feature vector use

combinedVector = [feature( : ), features2 ( : ), featureVector( : )]; 

[hajer jon]

I have got this error

"Dimensions of arrays being concatenated are not consistent"

[Sai Bhargav Avula]

It is because features extracted are of different length. Check for the lengths of each feature vector and pad accordingly to combine them. I would suggest you to go through the following link that combines matrices of different sizes.

https://www.mathworks.com/matlabcentral/answers/82907-combining-matrices-of-different-sizes

Hope this helps.