I have get a virtual env on ‘/home/name/pyenv’ for python2.7.9;
Now I want to install ‘matplotlib’ for it;
then I activate this virtual env and install ‘matplotlib’ as below:

• by command “sudo apt-get install python-matplotlib”;
  (if delete “sudo”, permission denied), it runs well and I find “matplotlib” is exactly installed, but it is for default python and not for virtual env(pyenv) ;

• by command “pip install matplotlib”

  I get error as below:

                  * The following required packages can not be built:
  
                  * freetype
  

Cleaning up…
Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-tYCFkL/matplotlib
Exception information:
Traceback (most recent call last):
File “/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/basecommand.py”, line 122, in main
status = self.run(options, args)
File “/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/commands/install.py”, line 290, in run
requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
File “/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/req.py”, line 1230, in prepare_files
req_to_install.run_egg_info()
File “/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/req.py”, line 326, in run_egg_info
command_desc=’python setup.py egg_info’)
File “/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/util.py”, line 716, in call_subprocess
% (command_desc, proc.returncode, cwd))
InstallationError: Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-tYCFkL/matplotlib

I want to install it by method 1, but i don;t know how to install it for virtual env.