Dear Özcan,
Thank you for your suggestions!
Option number two worked for me. I downloaded the tarball at
https://pypi.python.org/pypi/hcluster and installed it using sudo python setup.py install.
This message appeared in the terminal:
There are several valid include directories containing numpy/arrayobject.h
1: /usr/lib/python2.7/dist-packages
2: /usr/local/lib/python2.7/dist-packages
Selection [default=1]:
I selected 1.
Then, I went back and tried again with the recommended bash script. Finally I got the installation right. Thanks again!
Maryam