November 23, 2007

by rohanrs •
Uncategorized
• Tags: Functions And Special Characters, Functions And Special Operators, Operators

Clearly, it is important to know the language you intend to use. The language is described in the

manuals so I won’t repeat what they say, but I encourage you to type

help ops

help relop

help arith

help slash

at the command prompt and take a look at the list of operators, functions and special characters, and

look at the associated help pages.

When manipulating arrays in M AT L A B there are some operators and functions that are particu-

larely useful.

2.1 Operators

In addition to the arithmetic operators, M AT L A B provides a couple of other useful operators

The colon operator.

:

Type help colon for more information.

Non-conjugate transpose.

.”

Type help transpose for more information.

Complex conjugate transpose.

”

Type help ctranspose for more information.

Built-in functions

True if all elements of a vector are nonzero.

all

True if any element of a vector is nonzero.

any

Cumulative sum of elements.

cumsum

Diagonal matrices and diagonals of a matrix.

diag

Difference and approximate derivative.

diff

Last index in an indexing expression.

end

Identity matrix.

eye

Find indices of nonzero elements.

find

True for empty matrix.

isempty

True if arrays are numerically equal.

isequal

True for ï¬nite elements.

isfinite

True for inï¬nite elements.

isinf

True for logical array.

islogical

True for Not-a-Number.

isnan

True for numeric arrays.

isnumeric

Length of vector.

length

Convert numeric values to logical.

logical

Number of dimensions.

ndims

Number of elements in a matrix.

numel

Ones array.

ones

Permute array dimensions.

permute

Product of elements.

prod

Change size.

reshape

Size of matrix.

size

Sort in ascending order.

sort

Sum of elements.

sum

Extract lower triangular part.

tril

Extract upper triangular part.

triu

Zeros array.

zeros

Some of these functions are shorthands for combinations of other built-in functions, lik

is

length(x) max(size(x))

is

ndims(x) length(size(x))

is

numel(x) prod(size(x))

Others are shorthands for frequently used tests, like

is

isempty(x) numel(x) == 0

is

isinf(x) abs(x) == Inf

is

isfinite(x) abs(x) ~= Inf

Others are shorthands for frequently used functions which could have been written with low-level

code, like diag, eye, find, sum, cumsum, cumprod, sort, tril, triu, etc.

M-ï¬le functions

Flip matrix along speciï¬ed dimension.

flipdim

Flip matrix in left/right direction.

fliplr

Flip matrix in up/down direction.

flipud

Multiple subscripts from linear index.

ind2sub

Inverse permute array dimensions.

ipermute

Kronecker tensor product.

kron

Linearly spaced vector.

linspace

Generation of arrays for N-D functions and interpolation.

ndgrid

Replicate and tile an array.

repmat

Rotate matrix 90 degrees.

rot90

Shift dimensions.

shiftdim

Remove singleton dimensions.

squeeze

Linear index from multiple subscripts.

sub2ind

November 23, 2007

## Matlab Tips and Tricks-2

^{0}by rohanrs • Uncategorized • Tags: Functions And Special Characters, Functions And Special Operators, Operators

Clearly, it is important to know the language you intend to use. The language is described in the

manuals so I won’t repeat what they say, but I encourage you to type

help ops

help relop

help arith

help slash

at the command prompt and take a look at the list of operators, functions and special characters, and

look at the associated help pages.

When manipulating arrays in M AT L A B there are some operators and functions that are particu-

larely useful.

2.1 Operators

In addition to the arithmetic operators, M AT L A B provides a couple of other useful operators

The colon operator.

:

Type help colon for more information.

Non-conjugate transpose.

.”

Type help transpose for more information.

Complex conjugate transpose.

”

Type help ctranspose for more information.

Built-in functions

True if all elements of a vector are nonzero.

all

True if any element of a vector is nonzero.

any

Cumulative sum of elements.

cumsum

Diagonal matrices and diagonals of a matrix.

diag

Difference and approximate derivative.

diff

Last index in an indexing expression.

end

Identity matrix.

eye

Find indices of nonzero elements.

find

True for empty matrix.

isempty

True if arrays are numerically equal.

isequal

True for ï¬nite elements.

isfinite

True for inï¬nite elements.

isinf

True for logical array.

islogical

True for Not-a-Number.

isnan

True for numeric arrays.

isnumeric

Length of vector.

length

Convert numeric values to logical.

logical

Number of dimensions.

ndims

Number of elements in a matrix.

numel

Ones array.

ones

Permute array dimensions.

permute

Product of elements.

prod

Change size.

reshape

Size of matrix.

size

Sort in ascending order.

sort

Sum of elements.

sum

Extract lower triangular part.

tril

Extract upper triangular part.

triu

Zeros array.

zeros

Some of these functions are shorthands for combinations of other built-in functions, lik

is

length(x) max(size(x))

is

ndims(x) length(size(x))

is

numel(x) prod(size(x))

Others are shorthands for frequently used tests, like

is

isempty(x) numel(x) == 0

is

isinf(x) abs(x) == Inf

is

isfinite(x) abs(x) ~= Inf

Others are shorthands for frequently used functions which could have been written with low-level

code, like diag, eye, find, sum, cumsum, cumprod, sort, tril, triu, etc.

M-ï¬le functions

Flip matrix along speciï¬ed dimension.

flipdim

Flip matrix in left/right direction.

fliplr

Flip matrix in up/down direction.

flipud

Multiple subscripts from linear index.

ind2sub

Inverse permute array dimensions.

ipermute

Kronecker tensor product.

kron

Linearly spaced vector.

linspace

Generation of arrays for N-D functions and interpolation.

ndgrid

Replicate and tile an array.

repmat

Rotate matrix 90 degrees.

rot90

Shift dimensions.

shiftdim

Remove singleton dimensions.

squeeze

Linear index from multiple subscripts.

sub2ind