merged.
--- a/embellishing_a_plot.rst Fri Sep 17 18:38:51 2010 +0530
+++ b/embellishing_a_plot.rst Fri Sep 17 18:39:24 2010 +0530
@@ -16,7 +16,7 @@
on the terminal
-{{{ shit to terminal and type ipython -pylab }}}
+{{{ shift to terminal and type ipython -pylab }}}
We shall first make a simple plot and start with decorating it.
::
@@ -28,8 +28,10 @@
be nice if we could control these parameters in the plot. This is possible by
passing additional arguments to the plot command.
+.. #[[Anoop: I think it will be good to rephrase the sentence]]
+
The second argument that we shall be passing is colour. We shall first clear
-the figure and plot the same in red colour.Hence
+the figure and plot the same in red colour. Hence
::
clf()
@@ -38,17 +40,24 @@
Plots the same curve but now in red colour.
To alter the thickness of the line, we use the =linewidth= argument in the plot
-command.Hence
+command. Hence
::
plot(x, cos(x), linewidth=2)
produces a plot with a thicker line.
-{{{ Show the plot and compare the sin and cos plots }}}
+.. #[[Anoop: I guess it will be good if you say that it affects the
+ same plot, as you have not cleared the figure]]
+
+{{{ Show the plot and compare the sine and cos plots }}}
{{{ Pause here and try out the following exercises }}}
+.. #[[Anoop: is the above a context switch for the person who does the
+ recording, other wise if it an instruction to the person viewing the
+ video, then I guess the three braces can be removed.]]
+
%% 1 %% Plot sin(x) in blue colour and with linewidth as 3
{{{ continue from paused state }}}
@@ -58,11 +67,17 @@
plot(x, sin(x), 'b', linewidth=3)
+.. #[[Anoop: add clf()]]
+
produces the required plot
#[Nishanth]: I could not think of a SIMPLE recipe approach for introducing
linestyle. Hence the naive approach.
+.. #[[Anoop: I guess the recipe is fine, but would be better if you
+ add the problem statement rather than just saying "let's do a simple
+ plot"]]
+
Occasionally we would also want to alter the style of line. Sometimes all we
want is just a bunch of points not joined. This is possible by passing the
linestyle argument along with or instead of the colour argument.Hence
@@ -88,6 +103,8 @@
{{{ Pause here and try out the following exercises }}}
+.. #[[Anoop: same question as above, should it be read out?]]
+
%% 2 %% Plot the sine curve with green filled circles.
{{{ continue from paused state }}}
@@ -147,6 +164,8 @@
#[Nishanth]: Unsure if I have to give this exercise since enclosing the whole
string in LaTex style is not good
+.. #[[Anoop: I guess you can go ahead with the LaTex thing, it's cool!]]
+
{{{ Pause here and try out the following exercises }}}
%% 4 %% Change the title of the figure such that the whole title is formatted
@@ -210,6 +229,9 @@
like to mark the point as and the argument after xy= is the point at which the
name should appear.
+.. #[[Anoop: I think we should tell explicitely that xy takes a
+ sequence or a tuple]]
+
{{{ Pause here and try out the following exercises }}}
%% 6 %% Make an annotation called "root" at the point (-4, 0)
@@ -238,6 +260,6 @@
Thankyou
.. Author : Nishanth
- Internal Reviewer 1 :
+ Internal Reviewer 1 : Anoop
Internal Reviewer 2 :
External Reviewer :
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gettings_started_with_for.rst Fri Sep 17 18:39:24 2010 +0530
@@ -0,0 +1,217 @@
+.. 3.2 LO: getting started with =for= (2) [anoop]
+.. -----------------------------------------------
+.. * blocks in python
+.. + (indentation)
+.. * blocks in ipython
+.. + ... prompt
+.. + hitting enter
+.. * =for= with a list
+.. * =range= function
+
+=============================
+Getting started with for loop
+=============================
+
+{{{ show welcome slide }}}
+
+Hello and welcome to the tutorial getting started with ``for`` loop.
+
+{{{ switch to next slide, outline slide }}}
+
+In this tutorial we will see ``for`` loops in python, and also cover
+the basics of indenting code in python.
+
+{{{ switch to next slide, about whitespaces }}}
+
+In Python whitespace is significant, and the blocks are visually
+separated rather than using braces or any other mechanisms for
+defining blocks. And by this method Python forces the programmers to
+stick on to one way of writing or beautifying the code rather than
+debating over where to place the braces. This way it produces uniform
+code than obscure or unreadable code.
+
+A block may be defined by a suitable indentation level which can be
+either be a tab or few spaces. And the best practice is to indent the
+code using four spaces.
+
+Now let us move straight into ``for`` loop.
+
+{{{ switch to next slide, problem statement of exercise 1 }}}
+
+Write a for loop which iterates through a list of numbers and find the
+square root of each number. Also make a new list with the square roots
+and print it at the end.
+::
+
+ numbers are 1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916
+
+For the problem, first we need to create a ``list`` of numbers and
+then iterate over the list and find the square root of each element in
+it. And let us create a script, rather than typing it out in the
+interpreter itself. Create a script called list_roots.py and type the
+following.
+
+{{{ open the text editor and paste the following code there }}}
+::
+
+ numbers = [1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916]
+ square_roots = []
+ for each in numbers:
+ sq_root = sqrt(each)
+ print "Square root of", each, "is", sq_root
+ square_roots.append(sq_root)
+ print
+ print square_roots
+
+{{{ save the script }}}
+
+Now save the script, and run it from your IPython interpreter. I
+assume that you have started your IPython interpreter using ``-pylab``
+option.
+
+Run the script as,
+::
+
+ %run -i list_roots.py
+
+{{{ run the script }}}
+
+So that was easy! We didn't have to find the length of the string nor
+address of each element of the list one by one. All what we did was
+iterate over the list element by element and then use the element for
+calculation. Note that here we used three variables. One the variable
+``numbers``, which is a list, another one ``each``, which is the
+element of list under consideration in each cycle of the ``for`` loop,
+and then a variable ``sq_root`` for storing the square root in each
+cycle of the ``for`` loop. The variable names can be chosen by you.
+
+{{{ show the script which was created }}}
+
+Note that three lines after ``for`` statement, are indented using four
+spaces.
+
+{{{ highlight the threee lines after for statement }}}
+
+It means that those three lines are part of the for loop. And it is
+called a block of statements. And the seventh line or the immediate
+line after the third line in the ``for`` loop is not indented,
+
+{{{ highlight the seventh line - the line just after for loop }}}
+
+it means that it is not part of the ``for`` loop and the lines after
+that doesn't fall in the scope of the ``for`` loop. Thus each block is
+separated by the indentation level. Thus marking the importance of
+white-spaces in Python.
+
+{{{ switch to the slide which shows the problem statement of the first
+problem to be tried out }}}
+
+Now a question for you to try, from the given numbers make a list of
+perfect squares and a list of those which are not. The numbers are,
+::
+
+ 7225, 3268, 3364, 2966, 7056, 5625, 729, 5547, 7056, 576, 2916
+
+{{{ switch to next slide, problem statement of second problem in
+solved exercie}}}
+
+Now let us try a simple one, to print the square root of numbers in
+the list. And this time let us do it right in the IPython
+interpreter.
+
+{{{ switch focus to the IPython interpreter }}}
+
+So let us start with making a list. Type the following
+::
+
+ numbers = [1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916]
+ for each in numbers:
+
+and now you will notice that, as soon as you press the return key
+after for statement, the prompt changes to four dots and the cursor is
+not right after the four dots but there are four spaces from the
+dots. The four dots tell you that you are inside a block. Now type the
+rest of the ``for`` loop,
+::
+
+ sq_root = sqrt(each)
+ print "Square root of", each, "is", sq_root
+
+Now we have finished the statements in the block, and still the
+interpreter is showing four dots, which means you are still inside the
+block. To exit from the block press return key or the enter key twice
+without entering anything else. It printed the square root of each
+number in the list, and that is executed in a ``for`` loop.
+
+Now, let us generate the multiplication table of 10 from one to
+ten. But this time let us try it in the vanilla version of Python
+interpreter.
+
+Start the vanilla version of Python interpreter by issuing the command
+``python`` in your terminal.
+
+{{{ open the python interpreter in the terminal using the command
+python to start the vanilla Python interpreter }}}
+
+Start with,
+::
+
+ for i in range(1,11):
+
+and press enter once, and we will see that this time it shows four
+dots, but the cursor is close to the dots, so we have to intend the
+block. So enter four spaces there and then type the following
+::
+
+
+ print "10 *",i,"=",i*10
+
+Now when we hit enter, we still see the four dots, to get out of the
+block type enter once.
+
+Okay! so the main thing here we learned is how to use Python
+interpreter and IPython interpreter to specify blocks. But while we
+were generating the multiplication table we used something new,
+``range()`` function. ``range()`` is an inbuilt function in Python
+which can be used to generate a ``list`` of integers from a starting
+range to an ending range. Note that the ending number that you specify
+will not be included in the ``list``.
+
+Now, let us print all the odd numbers from 1 to 50. Let us do it in
+our IPython interpreter for ease of use.
+
+{{{ switch focus to ipython interpreter }}}
+
+{{{ switch to next slide, problem statement of the next problem in
+solved exercises }}}
+
+Print the list of odd numbers from 1 to 50. It will be better if
+you can try it out yourself.
+
+It is a very trivial problem and can be solved as,
+::
+
+ print range(1,51,2)
+
+This time we passed three parameters to ``range()`` function unlike
+the previous case where we passed only two parameters. The first two
+parameters are the same in both the cases. The first parameter is the
+starting number of the sequence and the second parameter is the end of
+the range. Note that the sequence doesn't include the ending
+number. The third parameter is for stepping through the sequence. Here
+we gave two which means we are skipping every alternate element.
+
+{{{ switch to next slide, recap slide }}}
+
+Thus we come to the end of this tutorial. We learned about blocks in
+Python, indentation, blocks in IPython, for loop, iterating over a
+list and then the ``range()`` function.
+
+{{{ switch to next slide, thank you slide }}}
+
+Thank you!
+
+.. Author: Anoop Jacob Thomas <anoop@fossee.in>
+ Reviewer 1:
+ Reviewer 2:
+ External reviewer:
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/other_types_of_plots.rst Fri Sep 17 18:39:24 2010 +0530
@@ -0,0 +1,220 @@
+.. 2.4 LO: other types of plots (3) [anoop]
+.. -----------------------------------------
+.. * scatter
+.. * pie chart
+.. * bar chart
+.. * log
+.. * illustration of other plots, matplotlib help
+
+===================
+Other type of plots
+===================
+
+{{{ show the first slide }}}
+
+Hello and welcome to the tutorial other type of plots.
+
+{{{ show the outline slide }}}
+
+In this tutorial we will cover scatter plot, pie chart, bar chart and
+log plot. We will also see few other plots and also introduce you to
+the matplotlib help.
+
+
+Let us start with scatter plot.
+
+{{{ switch to the next slide }}}
+
+In a scatter plot, the data is displayed as a collection of points,
+each having the value of one variable determining the position on the
+horizontal axis and the value of the other variable determining the
+position on the vertical axis. This kind of plot is also called a
+scatter chart, scatter diagram and scatter graph.
+
+Before we proceed further get your IPython interpreter running with
+the ``-pylab`` option. Start your IPython interpreter as
+::
+
+ ipython -pylab
+
+{{{ open the ipython interpreter in the terminal using the command
+ipython -pylab }}}
+
+{{{ switch to the next slide having the problem statement of first
+exercise }}}
+
+Now, let us plot a scatter plot showing the percentage profit of company A
+from the year 2000-2010. The data for the same is available in the
+file ``company-a-data.txt``.
+
+{{{ open the file company-a-data.txt and show the content }}}
+
+The data file has two lines with a set of values in each line, the
+first line representing years and the second line representing the
+profit percentages.
+
+{{{ close the file and switch to the terminal }}}
+
+To product the scatter plot first we need to load the data from the
+file using ``loadtxt``. We learned in one of the previous sessions,
+and it can be done as ::
+
+ year,profit = loadtxt('/home/fossee/other-plot/company-a-data.txt',dtype=type(int()))
+
+Now in-order to generate the scatter graph we will use the function
+``scatter()``
+::
+
+ scatter(year,profit)
+
+Notice that we passed two arguments to ``scatter()`` function, first
+one the values in x-coordinate, year, and the other the values in
+y-coordinate, the profit percentage.
+
+{{{ switch to the next slide which has the problem statement of
+problem to be tried out }}}
+
+Now here is a question for you to try out, plot the same data with red
+diamonds.
+
+**Clue** - *try scatter? in your ipython interpreter*
+
+.. scatter(year,profit,color='r',marker='d')
+
+Now let us move on to pie chart.
+
+{{{ switch to the slide which says about pie chart }}}
+
+A pie chart or a circle graph is a circular chart divided into
+sectors, illustrating proportion.
+
+{{{ switch to the slide showing the problem statement of second
+exercise question }}}
+
+Plot a pie chart representing the profit percentage of company A, with
+the same data from file ``company-a-data.txt``. So let us reuse the
+data we have loaded from the file previously.
+
+We can plot the pie chart using the function ``pie()``.
+::
+
+ pie(profit,labels=year)
+
+Notice that we passed two arguments to the function ``pie()``. The
+first one the values and the next one the set of labels to be used in
+the pie chart.
+
+{{{ switch to the next slide which has the problem statement of
+problem to be tried out }}}
+
+Now here is a question for you to try out, plot a pie chart with the
+same data with colors for each wedges as white, red, black, magenta,
+yellow, blue, green, cyan, yellow, magenta and blue respectively.
+
+**Clue** - *try pie? in your ipython interpreter*
+
+.. pie(t,labels=s,colors=('w','r','k','m','y','b','g','c','y','m','b'))
+
+{{{ switch to the slide which says about bar chart }}}
+
+Now let us move on to bar chart. A bar chart or bar graph is a chart
+with rectangular bars with lengths proportional to the values that
+they represent.
+
+{{{ switch to the slide showing the problem statement of third
+exercise question }}}
+
+Plot a bar chart representing the profit percentage of company A, with
+the same data from file ``company-a-data.txt``.
+
+So let us reuse the data we have loaded from the file previously.
+
+We can plot the bar chart using the function ``bar()``.
+::
+
+ bar(year,profit)
+
+Note that the function ``bar()`` needs at least two arguments one the
+values in x-coordinate and the other values in y-coordinate which is
+used to determine the height of the bars.
+
+{{{ switch to the next slide which has the problem statement of
+problem to be tried out }}}
+
+Now here is a question for you to try, plot a bar chart which is not
+filled and which is hatched with 45\ :sup:`o` slanting lines as shown
+in the image in the slide.
+
+**Clue** - *try bar? in your ipython interpreter*
+
+.. bar(year,profit,fill=False,hatch='/')
+
+{{{ switch to the slide which says about bar chart }}}
+
+Now let us move on to log-log plot. A log-log graph or log-log plot is
+a two-dimensional graph of numerical data that uses logarithmic scales
+on both the horizontal and vertical axes. Because of the nonlinear
+scaling of the axes, a function of the form y = ax\ :sup:`b` will
+appear as a straight line on a log-log graph
+
+{{{ switch to the slide showing the problem statement of fourth
+exercise question }}}
+
+
+Plot a `log-log` chart of y=5*x\ :sup:`3` for x from 1-20.
+
+Before we actually plot let us calculate the points needed for
+that. And it could be done as,
+::
+
+ x = linspace(1,20,100)
+ y = 5*x**3
+
+Now we can plot the log-log chart using ``loglog()`` function,
+::
+
+ loglog(x,y)
+
+To understand the difference between a normal ``plot`` and a ``log-log
+plot`` let us create another plot using the function ``plot``.
+::
+
+ figure(2)
+ plot(x,y)
+
+{{{ show both the plots side by side }}}
+
+So that was ``log-log() plot``.
+
+{{{ switch to the next slide which says: "How to get help on
+matplotlib online"}}}
+
+Now we will see few more plots and also see how to access help of
+matplotlib over the internet.
+
+Help about matplotlib can be obtained from
+matplotlib.sourceforge.net/contents.html
+
+.. #[[Anoop: I am not so sure how to do the rest of it, so I guess we
+ can just browse through the side and tell them few. What is your
+ opinion??]]
+
+Now let us see few plots from
+matplotlib.sourceforge.net/users/screenshots.html
+
+{{{ browse through the site quickly }}}
+
+{{{ switch to recap slide }}}
+
+Now we have come to the end of this tutorial. We have covered scatter
+plot, pie chart, bar chart, log-log plot and also saw few other plots
+and covered how to access the matplotlib online help.
+
+{{{ switch to the thank you slide }}}
+
+Thank you!
+
+.. Author: Anoop Jacob Thomas <anoop@fossee.in>
+ Reviewer 1:
+ Reviewer 2:
+ External reviewer: