### Using git to work on a project across OS and machines

If you're working for a company/team that develops a product that can be used on Windows, OS X and Linux, then you will have to test the changes you make on all three platforms to see if things are working the way you intend them to.

I presume that you're using version control, I personally use git, to manage the code base for the project. Say you make changes to the code base on an OSX machine and everything looks fine so you push the changes to a branch. Now, you will want to look at the changes on a different OS to make sure that the changes are behaving well, which you can do using

 1  git checkout --track / 

I hope you're familiar with  git checkout, which can be used to change to a different working branch or it can be used to remove changes made on a file on the current branch. The additional --track argument tells git to create a new branch from a remote branch, where the remote is usually set as origin. You're probably familiar with the -b argument which is used to create a new branch and move to it.

The above command might not work a 100% of the time. I'm still iffy on why it doesn't. I tried

 2  git pull origin master 

before running the first command, thinking that I'll have to tell git that upstream branches have been updated. But it didn't work. Instead, this command did the trick

 3  git fetch origin 

which seems to update all of the remote branches and tags.

Note : I used hilite.me to create the code blocks but sadly, they aren't highlighted the way I expected them to be. And here are two references. If you're interested in exploring git further, I strongly recommend the first of the two references.

### Animation using GNUPlot

Animation using GNUPlotI've been trying to create an animation depicting a quasar spectrum moving across the 5 SDSS pass bands with respect to redshift. It is important to visualise what emission lines are moving in and out of bands to be able to understand the color-redshift plots and the changes in it.
I've tried doing this using the animate function in matplotlib, python but i wasn't able to make it work - meaning i worked on it for a couple of days and then i gave up, not having found solutions for my problems on the internet.
And then i came across this site, where the gunn-peterson trough and the lyman alpha forest have been depicted - in a beautiful manner. And this got me interested in using js and d3 to do the animations and make it dynamic - using sliders etc.
In the meanwhile, i thought i'd look up and see if there was a way to create animations in gnuplot and whoopdedoo, what do i find but nirvana!

In the image, you see 5 static curves and one dynam…