Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: » https://pecl.php.net/package/svm
This is note is only for mac OSX
You need to have pear and libsvm installed first ..
brew install libsvm
sudo pecl install -f svm
now you need to edit php.ini and append
extension=svm.so
restart you php server