loading-data-from-files/questions.rst
author Puneeth Chaganti <punchagan@fossee.in>
Mon, 11 Oct 2010 01:01:16 +0530
changeset 279 5c9dc3419df5
parent 250 4d8ef03627b5
child 291 d83395820797
permissions -rw-r--r--
Slides for lstsq LO.

Objective Questions
-------------------

.. A mininum of 8 questions here. 

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")``

#. 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. 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?