Introductory Programming
Fall 2005

For today, you should have:

1) Read Chapter 4

Today:

1) matrices

For next time you should:

1) prepare for a quiz on matrices


Evaluation 2
------------

Generally pretty good.

Some people tried to use matrices and got confused.

Don't forget assignment statement 101:

1) left side is a variable

2) right side is an expression

3) don't be fooled by the equals sign

What's the difference between a statement and an expression?

1) an expression is a combination of operators and operands that
   has a value.  It gets evaluated, but it doesn't _do_ anything.

2) a statement does something; for example, an assignment statement
   gives a value to a variable.  Statements get executed.

Some functions are like expressions; they produce a value, but
they don't do anything:

sin(pi)        # computes a value, but has no lasting effect
               # on the workspace

y = sin(pi)    # this makes more sense

Some functions are like statements; they do something, but they
don't have a value.

plot(1:10)       # a window appears

z = plot(1:10)   # what is z?


Matrices
--------

Review of indices and elements.
Review of row and column vectors.
Review of matrix concatenation!
Review of plot.