Added questions to loading data from files LO.
authorPuneeth Chaganti <punchagan@fossee.in>
Fri, 08 Oct 2010 11:31:01 +0530
changeset 250 4d8ef03627b5
parent 249 cad8e64dcd82
child 251 9bc78792904b
Added questions to loading data from files LO.
loading-data-from-files/questions.rst
loading-data-from-files/script.rst
--- a/loading-data-from-files/questions.rst	Fri Oct 08 11:30:31 2010 +0530
+++ b/loading-data-from-files/questions.rst	Fri Oct 08 11:31:01 2010 +0530
@@ -1,17 +1,63 @@
-Objective
----------
+Objective Questions
+-------------------
 
 .. A mininum of 8 questions here. 
 
-1. Question 1
-2. Question 2
-3. Question 3
+1. ``loadtxt`` can read data only from a file with one column
+   only. True or False?
+
+   Answer: False
+
+#. To read a file with multiple columns, into separate simple
+   sequences, ``loadtxt`` is given the additional argument ______?
+
+   Answer: ``unpack=True``
+
+#. We have a file with two columns of data separated by one of the
+   following characters. Which of them doesn't require the delimiter
+   argument to be specified, when using ``loadtxt``. 
+
+   a. ;
+   #. , 
+   #. :
+   #. [space] 
+   
+   Answer: [space]
+   
+#. Given a file ``data.txt`` with three columns of data separated by
+   spaces, read it into one complex sequence. 
 
+   Answer: ``x = loadtxt("data.txt")``
 
-Programming
------------
+#. Given a file ``data.txt`` with three columns of data separated by
+   spaces, read it into 3 separate simple sequences. 
+
+   Answer: ``x = loadtxt("data.txt", unpack=True)``
+
+#. Given a file ``data.txt`` with three columns of data separated by
+   ``:``, read it into one complex sequence. 
+
+   Answer: ``x = loadtxt("data.txt", delimiter=":")``
+
+#. Given a file ``data.txt`` with three columns of data separated by
+   ":", read it into 3 separate simple sequences. 
+
+   Answer: ``x = loadtxt("data.txt", unpack=True, delimiter=":")``
+
+#. To use the loadtxt command, each row should have the same number of
+   values, T or F ?
+
+   Answer: True
+
+Larger Questions
+----------------
 
 .. A minimum of 2 questions here. 
 
-1. Programming Assignment 1
-2. Programming Assignment 2
+1. What will happen if one of the cells is empty?
+
+#. Read a column with text? 
+
+#. Given a file with 3 columns of data but two different delimiters,
+   what do you think will happen?
+
--- a/loading-data-from-files/script.rst	Fri Oct 08 11:30:31 2010 +0530
+++ b/loading-data-from-files/script.rst	Fri Oct 08 11:31:01 2010 +0530
@@ -81,7 +81,8 @@
 Now, let us use the ``loadtxt`` command to read a file that contains
 two columns of data, ``pendulum.txt``. This file contains the length
 of the pendulum in the first column and the corresponding time period
-in the second.
+in the second. Note that ``loadtxt`` needs both the columns to have
+equal number of rows. 
 
 .. Following is an exercise that you must do. 
 
@@ -139,9 +140,8 @@
 
 In this tutorial, we have learnt the basic use of the ``loadtxt``
 command, which is capable of doing a lot more than we have used it for
-until now, for example
-
-Following is an exercise that you must do. 
+until now. Let us look at an example, but before that do this
+exercise. 
 
 %%1%% Read the file ``pendulum_semicolon.txt`` which contains the same
 data as ``pendulum.txt``, but the columns are separated by semi-colons