MATLAB GLOSSARY
(as of August 31)
-----------------

MATLAB "Things":

  integers: 1, 2, 3
  real numbers: 1.23, -0.004, 5.67e8, 9.12E-4
  complex numbers: mathematically, "a+bi".  
  logical variables: have the value true or false
  strings: 'a', 'Baby', 'Cat in a hat.'

Special Names:

  eps        the smallest number you can add to 1; 
  pi
  Inf        the result of computations like 1/0
  NaN        the result of computations like 0/0
  realmax    the largest real number MATLAB can handle
  realmin    the smallest positive real number MATLAB can handle

Arithmetic:

  A + 1     B - 2.3   C * D     E / F    G^2

Math functions:

  y = abs ( x )
  y = acos ( x )
  y = asin ( x )
  y = atan ( x )
  y = ceil ( x )          round a real number up to an integer
  y = cos ( x )
  y = exp ( x )
  y = factorial ( n )     1*2*3*...*n
  y = floor ( x )         round a real number down to an integer
  y = gcd ( m, n )        Greatest common divisor;  gcd(30,24) is 6.
  tf = isprime ( n )      true if integer n is a prime number.
  y = lcm ( m, n )        Least common multiple;    lcm(6,20) is 60.
  y = log ( x )
  z = max ( x, y )
  z = min ( x, y )
  r = mod ( x, y )        remainder from division x/y   mod(32,5) is 2
  y = rand ( )            return a random number between 0 and 1.
  y = round ( x )         round a real number to the nearest integer
  y = sin ( x )
  y = sqrt ( x )
  y = tan ( x )

Assignment statements:

      sqrt(x)    computes the value, stores it as "ans", displays it.
  y = sqrt(x)    computes the value, stores it as "y", displays it.
  y = sqrt(x);   computes the value, stores it as "y".

Logical operators:

  x <  y
  x <= y
  x >  y
  x >= y
  x == y            x is equal to y
  x ~= y            x is not equal to y

  x < y && y < z          x is less than y AND y is less than z   
  x < y || y < z          x is less than y OR  y is less than z
  ~ ( x == 0 && y == 0 )  it's NOT the case that both x and y are zero.

Logical control:

  if ( x < y )
    fprintf ( ' X is smaller than Y!\n' );
  end

  if ( x <= y && y <= z )
    disp ( '  Y is between X and Z.' )
  end

  if ( 0 <= x )
    y = sqrt ( x );
  else
    y = sqrt ( -x );
  end

  if ( 0 <= x )
    pos = pos + 1;
  elseif ( x == 0 )
    zero = zero + 1;
  else
    neg = neg + 1;
  end

Printing:

  x                                           displays x (unformatted)
  x;                                          no display
  y = x + 1                                   sets y, and displays y (unformatted)
  y = x + 1;                                  sets y, no display

  fprintf ( '  The value of x is %f', x );    Prints
  fprintf ( '  The value of x is %f\n', x );  Prints, then starts new line.

  format long                                 16 digit real printout
  format short                                6 digits real printout

  disp ( 'Can''t divide by zero!' )           Displays a string.
  fprintf ( 'Can''t divide by zero!\n' );     Also displays a string.

  disp ( '' )                                 Prints a blank line.
  fprintf ( '\n' );                           Prints a blank line.

Formats used in FPRINTF:

  %f     print a real number with "fixed point" format.
  %10f   print a real number, using 10 spaces
  %7.2f  print a real number, using 7 spaces, with 2 decimal places

  %e     print a real number with "exponential" format.
  %g     print a real number with "general" format (fixed or exponential).

  %d     print an integer; if real, only print integer part.
  %10d   print an integer using 10 spaces

Miscellaneous:

  x = input ( 'Enter a value for x:' )  asks user to input value (for scripts)
  error ( 'Message' )                   print message, terminate script.

  clear     clears MATLAB's memory; all variable values are lost.
  clc       clears the command window.
  %         used to begin a comment
  help sin  brief help on "sin" function
  doc sin   extensive help on "sin" function
  ...       continue this text on a new line
  exit      exits MATLAB completely.
  Ctrl-C    force MATLAB to stop the current computation.

  pwd            what is the full name of MATLAB's current directory?
  cd ..          move MATLAB's current directory up one level
  cd dirname     move MATLAB's current directory to "dirname"
  ls             list the files in the current directory
  dir            list the files in the current directory
  type filename  type the contents of the file "filename"

Parentheses:

  A + B * C
  ----------  must be written ( a + b * c ) / ( d + e )
  D + E

  F + G
  -----       must be written ( f + g ) / ( 2 * h )
  2 H

                  2
 1     - ( x - y )
 -   e              must be written ( 1 / 2 ) * exp ( - ( ( x - y )^2 ) )
 2 

     2 
  sin  pi x         must be written ( sin ( pi * x ) ) ^ 2