--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/additional_features_of_ipython/script.rst Wed Dec 01 16:51:35 2010 +0530
@@ -0,0 +1,219 @@
+.. Objectives
+.. ----------
+
+.. By the end of this tutorial you will be able to
+
+.. #. Retrieve your ipython history
+.. #. View a part of the history
+.. #. Save a part of your history to a file.
+.. #. Run a script from within ipython
+
+
+.. Prerequisites
+.. -------------
+
+.. 1. Embellishing Plots
+
+.. Author : Nishanth Amuluru
+ Internal Reviewer : Amit
+ External Reviewer :
+ Language Reviewer : Bhanukiran
+ Checklist OK? : <15-11-2010, Anand, OK> [2010-10-05]
+
+Script
+------
+
+Hello friends and welcome to the tutorial on Additional Features of IPython
+
+{{{ Show the slide containing title }}}
+
+{{{ Show the slide containing the outline slide }}}
+
+In this tutorial, we shall look at additional features of IPython that help us
+to retreive the commands that we type on the interpreter and then save them
+into a file and run it.
+
+Let us start ipython with pylab loaded, by typing
+::
+
+ $ ipython -pylab
+
+on the terminal
+
+{{{ shift to terminal and type ipython -pylab }}}
+
+We shall first make a plot and then view the history and save it.
+::
+
+ x = linspace(-2*pi, 2*pi, 100)
+ plot(x, xsinx(x))
+
+xsin(x) is actually x * sin(x)
+::
+
+ plot(x, x*sin(x))
+ plot(x, sin(x))
+ xlabel("x")
+ ylabel("$f(x)$")
+ title("x and xsin")
+
+We now have the plot. Let us look at the commands that we have typed in. The
+history can be retreived by using =%hist= command. Type
+::
+
+ %hist
+
+As you can see, it displays a list of recent commands that we typed. Every
+command has a number in front, to specify in which order and when it was typed.
+
+Please note that there is a % sign before the hist command. This implies that
+%hist is a command that is specific to IPython and not available in the vannila
+Python interpreter. These type of commands are called as magic commands.
+
+Also note that, the =%hist= itself is a command and is displayed as the most
+recent command. We should not that anything we type in is stored as history,
+irrespective of whether it is command or an error or IPython magic command.
+
+If we want only the recent 5 commands to be displayed, we pass the number as an argument
+to =%hist= command. Hence
+::
+
+ %hist 5
+
+displays the recent 5 commands, inclusive of the =%hist= command.
+The default number is 40.
+
+{{{ Pause here and try out the following exercises }}}
+
+%% 1 %% Read through the documentation of %hist and find out how to
+ list all the commands between 5 and 10
+
+{{{ continue from paused state }}}
+
+As we can see from =%hist= documentation,
+::
+
+ %hist 5 10
+
+displays the commands from 5 to 10
+
+Now that we have the history, we would like to save the required line of code
+from history. This is possible by using the =%save= command.
+
+Before we do that, let us first look at history and identify what lines of code we require.Type
+::
+
+ %hist
+
+
+{{{ point to the lines }}}
+
+The first command is linspace. But second command is a command that gave us an
+error. Hence we do not need second command. The commands from third to sixth are
+required. The seventh command although is correct, we do not need it since we
+are setting the title correctly in the eigthth command.
+
+So we need first third to sixth and the eigthth command for our program.
+Hence the syntax of =%save= is
+::
+
+ %save /home/fossee/plot_script.py 1 3-6 8
+
+{{{ point to the output of the command }}}
+
+The command saves first and then third to sixth and eighth lines of code into
+the specified file.
+
+The first argument to %save is the path of file to save the commands and the
+arguments there after are the commands to be saved in the given order.
+
+{{{ goto the file and open it and show it }}}
+
+{{{ Pause here and try out the following exercises }}}
+
+%% 2 %% Change the label on y-axis to "y" and save the lines of code
+ accordingly
+
+{{{ continue from paused state }}}
+
+we use the command =ylabel= on interpreter as
+::
+
+ ylabel("y")
+
+and then do
+::
+
+ %save /home/fossee/example_plot.py 1 3-6 10
+
+Now that we have the required lines of code in a file, let us learn how to run
+the file as a python script.
+
+We use the IPython magic command =%run= to do this. Type
+::
+
+ %run -i /home/fossee/plot_script.py
+
+The script runs but we do not see the plot. This happens because when we are running
+a script and we are not in interactive mode anymore.
+
+Hence on your terminal type
+::
+
+ show()
+
+to show the plot.
+
+{{{ Pause here and try out the following exercises }}}
+
+%% 3 %% Use %hist and %save and create a script that has show in it and run it
+ to produce and show the plot.
+
+
+{{{ continue from paused state }}}
+
+We first look at the history using
+::
+
+ %hist 20
+
+Then save the script using
+::
+
+ %save /home/fossee/show_included.py 1 3-6 8 10 13
+ %run -i /home/fossee/show_included.py
+ show()
+
+We get the desired plot.
+
+The reason for including a -i after run is to tell the interpreter that if any
+name is not found in script, search for it in the interpreter. Hence all these
+sin, plot, pi and show which are not available in script, are taken from the
+interpreter and used to run the script.
+
+{{{ Pause here and try out the following exercises }}}
+
+%% 4 %% Run the script without using the -i option. Do you find any difference?
+
+{{{ continue from paused state }}}
+
+We see that it raises NameError saying that the name linspace is not found.
+
+{{{ Show summary slide }}}
+
+This brings us to the end of the tutorial.
+we have looked at
+
+ * Retreiving history using =%hist= command
+ * Vieweing only a part of history by passing an argument to %hist
+ * saving the required lines of code in required order using %save
+ * using %run -i command to run the saved script
+
+{{{ Show the "sponsored by FOSSEE" slide }}}
+
+
+This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
+
+Hope you have enjoyed and found it useful.
+Thank You!
+