LAB 1 General MATLAB Information

General:
To enter a matrix:
> type the entries between square brackets, [.....]
> enter it by rows with elements separated by a space or comma
> rows are terminated by a semicolon

command A= [1 2 3;4 5 6;7 8 9] displays

Suppressing Displays: When you place a semicolon at the end of a command, the
command will be executed but the result will not be displayed on the screen. This is
very useful when you are creating big matrices or to not reveal intermediate steps of
a calculation . Try typing the command

w = linspace(1,20,100); Note the semicolon

to create a row vector with equally spaced entries. The contents of w will not be
displayed. To see the contents just type w.

To enter a string: type the contents of the string between single quotes ' ... '

command st = 'Hi there.' displays st =
Hi there.

Strings are not commands.
Strings supply information.
Strings are used for messages and formulas .

What you see on the screen: MATLAB has various display formats. That is, ways to
show things on the screen. All numerical values stored by MATLAB have about 16
decimal places . However, we do not always want to see all the decimals places. That is
why MATLAB has display formats.

The default format is format short.
Format short shows 4 places behind the decimal point for reasonable sized numbers.
Examples:
pi is shown as 3.1416 in format short
2/3 is shown as 0.6667 in format short
1/8 is shown as 0.1250 in format short
(Format short rounds to obtain the last digit which is displayed. Beware, there may be
many more decimal places than those shown.)

Examples of other display formats: (e formats or floating point formats display a
number and an exponent which is a power of ten ; 1.2345e+002 means 1.2345*10² )

FORMAT SHORT Scaled fixed point format with 5 digits.
FORMAT LONG Scaled fixed point format with 15 digits.
FORMAT SHORT E Floating point format with 5 digits.
FORMAT LONG E Floating point format with 15 digits.
FORMAT SHORT G Best of fixed or floating point format with 5 digits.
FORMAT LONG G Best of fixed or floating point format with 15 digits.
FORMAT RAT Approximation by ratio of small integers.

format short e shows pi as 3.1416e+000
format long shows pi as 3.14159265358979
format long e shows pi as 3.141592653589793e+000
format rat   shows pi as 355/113

Note: 355/113 is only an approximation to pi; computing 355/113 in format long gives
3.14159292035398

Use command help format for the description of other display formats.

Illustrations of ALGEBRA Expressions and their MATLAB form.

Standard Algebra Form	MATLAB Representation
3x2 - 5x + 1	3*x^2-5*x+1 multiplication must be indicated using * and exponents require an ^
	(2*x-3)/(4-7*x) the numerator and denominator must be enclosed in parentheses if they are more than 1 term
	sqrt(x^2+1) or (x^2+1)^.5 or (x^2+1)^(1/2) using sqrt is preferred; fractional exponents must be enclosed in parentheses
	exp(-x)
ln(x)	log(x) the natural log function is denoted log; log base 10 is denoted log10
cos2(x - π)	cos(x-pi)^2 constant π is denoted pi; all arguments of trig. functions are considered radians
sin(x) e-2.3x	sin(x)*exp(-2.3*x) note that the exponent is in parentheses and that we must use * to indicate multiplication
|tan(x)|	abs(tan(x)) the absolute value is denoted by abs; parentheses must be used

Operators, Elementary Functions, & General Purpose Commands