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Ureka – one package to install them all!

Among the simplest installation methods to install IRAF are SciSoft (for RedHat/Fedora based distributions) and Fernando Avila Castro iso files (for Ubuntu/Debian based distributions). However, both require root privileges. What can you do when you do not have these permissions?

Ureka [1] comes in rescue! It is easy to install (download and run the installer![2]) and it doesn’t need any root privileges, so you can install it under your home directory.

Moreover, it offers, along with a simple installation of IRAF, a full installation of Python, with many pre-installed modules useful to perform almost any astronomical reduction (e.g. PyRAF, Astropy, matplotlib, pandas, [more]).

By default Ureka (1.4.1) installs with a Python version (2.7.3), and it modifies your shell starting scripts (bashrc,tcshrc) to create the aliases to use. E.g. the added lines in a .bashrc file are:

ur_setup() {
    eval `/var/home/maravelias/.ureka/ur_setup -sh $*`
ur_forget() {
    eval `/var/home/maravelias/.ureka/ur_forget -sh $*`

and you can invoke Ureka by simple typing: ur_setup. Now, this means that in every shell that you start you will have to type over and over again the same command, which becomes at least frustrating. In order to avoid this, you can simply comment the alias line:

#ur_setup() {
eval `/var/home/maravelias/.ureka/ur_setup -sh $*`
ur_forget() {
    eval `/var/home/maravelias/.ureka/ur_forget -sh $*`

so Ureka starts with every shell now. This option allows Python to install any extra modules (through PyPI – pip install) to the Ureka path and not system’s Python path.

Ureka allows for multiple installations of difference versions or different variants so there is reasoning in using the alias – but still for many users it may not be necessary (in any case you just uncomment the lines and you get back to the normal use).

So, Ureka offers an easy and clean way to install IRAF and a powerfull Python installation at the same time, without any root permissions. The only drawback is that it needs a lot of space (~4-5 GB), but it does not seem dramatic nowadays. [As far as the sys-admins it is easier to provide you with more extra space rather than software installations/updates within their systems.]

[1] Ureka: http://ssb.stsci.edu/ureka/
[2] Documentation 1.4: http://ssb.stsci.edu/ureka/1.4.1/docs/index.html

Installing matplotlib through pip but no plot displayed

The easiest way to install any Python package is through PyPI. So, matplotlib is not an exception and we installed it on a CentOS (v6.4) machine without any errors (of course after updating numpy).

But when we tried to plot something we couldn’t see anything. This is actually a backend issue, and when we installed matplotlib there was no support for any backend (except the default agg which is supplied with matplotlib).

To solve this, we first installed the pygtk-dev version and then re-istalled matplotlib, through

pip install matplotlib

which was build now with the GTKAgg as default backend.

Happy plotting !