st-scripts: comparison getting-started-with-arrays/script.rst

equal deleted inserted replaced

-:1353cbda5969
+:f99254fc7d70
 Welcome to the spoken tutorial on getting started with arrays.
 {{{ switch to next slide, outline slide }}}
-In this tutorial, we will learn about arrays, how to convert a list into an
+In this tutorial, we will learn about arrays, we will learn how to convert
-array and also why an array is preferred over lists. And array operations.
+a list into an array array operations and also why an array is preferred
+over lists.
 .. #[Puneeth: Fix the grammar above.]
 {{{ switch to next slide on overview of array }}}
-Arrays are homogeneous data structures, unlike lists, arrays cannot have
+Arrays are homogeneous data structures. Unlike lists, arrays cannot have
 heterogeneous data elements, that is, it can have only one type of data
 type, either all integers, or strings, or float, and not a mix.
 .. #[Puneeth: Use multiple short sentences, rather than one long sentence
 I would've written something like this.
 Unlike lists, arrays are homogeneous data structures. They can have only
 type of data, ....]
 Arrays are really fast in mathematical operations when compared to lists,
-it is at least 80 to 100 times faster than lists.
+because of the same type of data in arrays.
 .. #[Puneeth: For what size of an array is that the comparison?
 {{{ switch to the next slide, creating arrays }}}
 Now let us see how to create arrays.
-I am assuming that you have your IPython interpreter running with the
+Run your IPython interpreter with ``-pylab`` option, to load the required
-``-pylab`` option, so that you have the required modules loaded.
+modules to work with arrays.
+{{{ take terminal and run the following command }}}
+::
+ipython -pylab
 .. #[Puneeth: 'I am assuming' doesn't sound right. Ask them to open if it
 .. is not open?]
 To create an array we will use the function ``array()`` as,
 ::
 a1 = array([1,2,3,4])
 Notice that here we created a one dimensional array. Also notice the object
-we passed to create an array. Now let us see how to create a two
+we passed to create an array. We passed a list to create an array.
-dimensional array. Pause here and try to do it yourself before looking at
-the solution.
+Now let us see how to create a two dimensional array. Pause here and try to
+do it yourself before looking at the solution.
+{{{ switch to next slide, creating two dimensional arrays }}}
 .. #[Puneeth: I don't think this question can be solved by an average
 .. viewer. Questions during the tutorial, should generally be to re-iterate
 .. concepts learnt? ]
 .. #[Puneeth: Also, you didn't even point out that we are converting a
 .. list, using the ``array`` function. Bring the later section about
 .. converting a list, here. A separate section is not necessary, IMHO.]
-This is how we create two dimensional arrays.
+We create two dimensional array by converting a list of lists to an array
+as,
 ::
 a2 = array([[1,2,3,4],[5,6,7,8]])
 .. #[Puneeth: Again, you could explain a bit about the fact that we are
 .. converting a list of lists.]
-Let us see an easy method of creating an array with elements 1 to 8.
+Now let us use ``arange()`` function to create the same array as before.
 ::
 ar = arange(1,9)
 .. #[Puneeth: say, creating the same array as before. for some time I got
 .. confused .]
-And it created a single dimensional array of elements from 1 to 8.
+And we obtained a single dimensional array with elements from 1 to 8.
 ::
 print ar
 .. #[Puneeth: s/object/method ?]
 ::
-a1.shape
+a2.shape
-``a1.shape`` object is a tuple, and since a1 is a single dimensional array,
+``a2.shape`` object is a tuple, and it returned a tuple (2, 4).
-it returned a tuple (4,).
 .. #[Puneeth: first show a 2D array, so that it becomes easier to explain.
 .. Also, the word ``tuple`` need not be mentioned. ]
 {{{ switch to the next slide, unsolved exercise 2 }}}
 Find out the shape of the other arrays that we have created.
 .. #[Puneeth: solution missing.]
+It can be done as,
+::
+a1.shape
+a3.shape
+ar.shape
 {{{ Array can have only a single type of data }}}
 .. #[Puneeth: I guess, this whole section can be skipped. If you want to
 .. keep this, just briefly mention that arrays are homogeneous in the
 {{{ switch to the next slide, identity & zeros methods }}}
 .. #[Puneeth: something needs to motivate this. why are we suddenly talking
 .. of an identity matrix?]
-An identity matrix is a square matrix in which all the diagonal elements
+Now let us see how to create identity matrix, an identity matrix is a
-are one and rest of the elements zero. We can create an identity matrix
+square matrix in which all the diagonal elements are one and rest of the
-using the method ``identity()``.
+elements zero. We can create an identity matrix using the method
+``identity()``.
 The function ``identity()`` takes an integer argument,
 ::
 identity(3)
-As you can see the identity method returned a three by three square array
+As you can see the identity method returned a three by three square matrix
 with all the diagonal elements as one and the rest of the elements as zero.
 .. #[Puneeth: You say array here, matrix there -- it's a bit messed up.
 .. Clarify, explicitly.]
 does not perform matrix multiplication.
 {{{ switch to next slide, summary slide }}}
 So this brings us to the end of this tutorial, in this tutorial we covered
-basics of arrays, how to create an array, converting a list to an array,
+basics of arrays, learned how to create an array, saw how to convert a list
-basic array operations etc.
+to an array, and basic array operations etc.
 .. #[Puneeth: s/how to create an array/creating an array]
 {{{ switch to next slide, thank you }}}

changeset 393	f99254fc7d70
parent 319	e8c02b3c51ac
child 475	2e0b89c0eeb4