Basic Mathematical Operations
1.7
2006/02/20 13:57:47 US/Central
2006/09/06 14:03:29.561 GMT-5
Anders
Gjendemsjø
gjendems@iet.ntnu.no
Darryl
Morrell
morrell@asu.edu
Darryl
Morrell
morrell@asu.edu
LabVIEW MathScript
mathematical operations
MATLAB
Octave
This module covers basic mathematical operations in an m-file environment.
Operations and Expressions
An m-file environment has all of the standard arithmetic operations (addition, subtraction, etc.) and functions (sine, cosine, logarithm, etc.). The table lists the most commonly used operations; in this table, x and y are scalars. (A scalar is a single value, as opposed to a vector or matrix which consists of many values.)
Some Common Scalar Mathematical Operations
Operation
m-file
xy
x-y
xy
x+y
xy
x*y
xy
x/y
xy
x^y
ex
exp(x)
log10x
log10(x)
lnx
log(x)
log2x
log2(x)
x
cos(x)
x
sin(x)
x
sqrt(x)
Expressions are formed from numbers, variables, and these operations. The operations have different precedences. The ^ operation has the highest precedence; ^ operations are evaluated before any other operations. Multiplication and division have the next highest precedence, and addition and subtraction have the lowest precedence. Precedence is altered by parentheses; expressions within parentheses are evaluated before expressions outside parentheses.
The Table below shows several mathematical formulas, the corresponding expressions, and the values that are computed for the expressions.
Example Expressions
formula
MATLAB Expression
Computed Value
52
42
5^2+4^2
41
54
2
(5+4)^2
81
23
45
(2 + 3)/(4 - 5)
-5
log10
100
log10(100)
2
ln
4
23
log(4*(2+3))
2.9957
Useful Tricks
These tricks are occasionally useful, especially when you begin programming with m-files.
- A semicolon added at the end of a line suppresses the output.
- Often it is useful to split input over multiple lines. To split a statement across multiple lines, enter three periods
... at the end of the line to indicate it continues on the next line.
Splitting the expression
23
45
over multiple lines.
(2+3)...
/(4-5)