Lab 4
CS100M/CIS121/EAS121 Spring 2004
Due Friday, Feb 27, 23:59 pm (due to popular demand)

1) Answer questions about Prelim 1 [about 10 min].

2) Answer questions about recent topics (arrays) [5-10 min].

3) All about arrays:

   a) Create a 2x3 2-D array filled with random integers between
      0 and 9 (inclusive). Use RAND! (Someone's probably thinking about literally
      typing in 6 random integers :-) Assign this array to x.

   b) Square each element of x using one statement.

   c) Show how to transpose x. Now, pretend MATLAB removed the
      transpose operator...Write a nested for-loop
      that stores the transpose of x in y.

   d) Swap the 1st and 2nd rows of x. Do not use another variable.

   e) Replace the third column of x with the second and first elements
      of the second row of x (in that order). Use an index operation
      to extract those row elements! Store the results in x.

   f) Write a program that removes all non-alphabetic characters from
      a string that a user inputs. Use vectorization! Store the new
      string in s.