Manual de Octave: Comandos básicos - Apuntes de Arquitectura

Octave Quick Reference Octave Version 3.0.0

Starting Octave

octave start interactive Octave session

octave file run Octave on commands in file

octave --eval code Evaluate code using Octave

octave --help describe command line options

Stopping Octave

quit or exit exit Octave

INTERRUPT (e.g. C-c) terminate current command and

return to top-level prompt

Getting Help

help list all commands and built-in variables

help command briefly describe command

doc use Info to browse Octave manual

doc command search for command in Octave manual

lookfor str search for command based on str

Motion in Info

SPC or C-v scroll forward one screenful

DEL or M-v scroll backward one screenful

C-l redraw the display

Node Selection in Info

nselect the next node

pselect the previous node

uselect the ‘up’ node

tselect the ‘top’ node

dselect the directory node

<select the first node in the current file

>select the last node in the current file

greads the name of a node and selects it

C-x k kills the current node

Searching in Info

ssearch for a string

C-s search forward incrementally

C-r search backward incrementally

isearch index & go to corresponding node

,go to next match from last ‘i’ command

Command-Line Cursor Motion

C-b move back one character

C-f move forward one character

C-a move to the start of the line

C-e move to the end of the line

M-f move forward a word

M-b move backward a word

C-l clear screen, reprinting current line at top

Inserting or Changing Text

M-TAB insert a tab character

DEL delete character to the left of the cursor

C-d delete character under the cursor

C-v add the next character verbatim

C-t transpose characters at the point

M-t transpose words at the point

[ ] surround optional arguments ... show one or more arguments

Killing and Yanking

C-k kill to the end of the line

C-y yank the most recently killed text

M-d kill to the end of the current word

M-DEL kill the word behind the cursor

M-y rotate the kill ring and yank the new top

Command Completion and History

TAB complete a command or variable name

M-? list possible completions

RET enter the current line

C-p move ‘up’ through the history list

C-n move ‘down’ through the history list

M-< move to the first line in the history

M-> move to the last line in the history

C-r search backward in the history list

C-s search forward in the history list

history [-q] [N]list Nprevious history lines, omitting

history numbers if -q

history -w [file]write history to file (~/.octave hist if no

file argument)

history -r [file]read history from file (~/.octave hist if

no file argument)

edit history lines edit and then run previous commands

from the history list

run history lines run previous commands from the history

list

[beg] [end]Specify the first and last history

commands to edit or run.

If beg is greater than end, reverse the list of commands

before editing. If end is omitted, select commands from

beg to the end of the history list. If b oth arguments are

omitted, edit the previous item in the history list.

Shell Commands

cd dir change working directory to dir

pwd print working directory

ls [options]print directory listing

getenv (string)return value of named environment

variable

system (cmd)execute arbitrary shell command string

Matrices

Square brackets delimit literal matrices. Commas separate

elements on the same row. Semicolons separate rows. Commas

may be replaced by spaces, and semicolons may be replaced by

one or more newlines. Elements of a matrix may be arbitrary

expressions, assuming all the dimensions agree.

[x,y, ... ] enter a row vector

[x;y; ... ] enter a column vector

[w,x;y,z]enter a 2×2 matrix

Multi-dimensional Arrays

Multi-dimensional arrays may be created with the cat or

reshape commands from two-dimensional sub-matrices.

squeeze (arr)remove singleton dimensions of the array.

ndims (arr)number of dimensions in the array.

permute (arr,p)permute the dimensions of an array.

ipermute (arr,p)array inverse permutation.

shiftdim (arr,s)rotate the array dimensions.

circshift (arr,s)rotate the array elements.

Sparse Matrices

sparse (...) create a sparse matrix.

speye (n) create sparse identify matrix.

sprand (n,m,d)sparse rand matrix of density d.

spdiags (...) sparse generalization of diag.

nnz (s)No. non-zero elements in sparse matrix.

Ranges

base :limit

base :incr :limit

Specify a range of values beginning with base with no

elements greater than limit. If it is omitted, the default

value of incr is 1. Negative increments are permitted.

Strings and Common Escape Sequences

Astring constant consists of a sequence of characters enclosed

in either double-quote or single-quote marks. Strings in double-

quotes allow the use of the escape sequences below.

\\ a literal backslash

\" a literal double-quote character

\’ a literal single-quote character

\n newline, ASCII code 10

\t horizontal tab, ASCII code 9

Index Expressions

var (idx)select elements of a vector

var (idx1,idx2)select elements of a matrix

scalar select row (column) corresponding to

scalar

vector select rows (columns) corresponding to the

elements of vector

range select rows (columns) corresponding to the

elements of range

:select all rows (columns)

Global and Persistent Variables

global var1 ... Declare variables global.

global var1 =val Declare variable global. Set intial value.

persistent var1 Declare a variable as static to a function.

persistent var1 =

val

Declare a variable as static to a function

and set its initial value.

Global variables may be accessed inside the body of a function

without having to be passed in the function parameter list

provided they are declared global when used.

Selected Built-in Functions

EDITOR editor to use with edit history

Inf, NaN IEEE infinity, NaN

NA Missing value

PAGER program to use to paginate output

ans last result not explicitly assigned

eps machine precision

pi π

1i √−1

realmax maximum representable value

realmin minimum representable value

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Octave Quick Reference Octave Version 3.0.

Starting Octave

octave start interactive Octave session

octave file run Octave on commands in file

octave --eval code Evaluate code using Octave

octave --help describe command line options

Stopping Octave

quit or exit exit Octave

INTERRUPT (e.g. C-c) terminate current command and

return to top-level prompt

Getting Help

help list all commands and built-in variables

help command briefly describe command

doc use Info to browse Octave manual

doc command search for command in Octave manual

lookfor str search for command based on str

Motion in Info

SPC or C-v scroll forward one screenful

DEL or M-v scroll backward one screenful

C-l redraw the display

Node Selection in Info

n select the next node

p select the previous node

u select the ‘up’ node

t select the ‘top’ node

d select the directory node

< select the first node in the current file

> select the last node in the current file

g reads the name of a node and selects it

C-x k kills the current node

Searching in Info

s search for a string

C-s search forward incrementally

C-r search backward incrementally

i search index & go to corresponding node

, go to next match from last ‘i’ command

Command-Line Cursor Motion

C-b move back one character

C-f move forward one character

C-a move to the start of the line

C-e move to the end of the line

M-f move forward a word

M-b move backward a word

C-l clear screen, reprinting current line at top

Inserting or Changing Text

M-TAB insert a tab character

DEL delete character to the left of the cursor

C-d delete character under the cursor

C-v add the next character verbatim

C-t transpose characters at the point

M-t transpose words at the point

[ ] surround optional arguments ... show one or more arguments

Killing and Yanking

C-k kill to the end of the line

C-y yank the most recently killed text

M-d kill to the end of the current word

M-DEL kill the word behind the cursor

M-y rotate the kill ring and yank the new top

Command Completion and History

TAB complete a command or variable name

M-? list possible completions

RET enter the current line

C-p move ‘up’ through the history list

C-n move ‘down’ through the history list

M-< move to the first line in the history

M-> move to the last line in the history

C-r search backward in the history list

C-s search forward in the history list

history [-q] [N ] list N previous history lines, omitting

history numbers if -q

history -w [file] write history to file (~/.octave hist if no

file argument)

history -r [file] read history from file (~/.octave hist if

no file argument)

edit history lines edit and then run previous commands

from the history list

run history lines run previous commands from the history

list

[beg] [end] Specify the first and last history

commands to edit or run. If beg is greater than end, reverse the list of commands before editing. If end is omitted, select commands from beg to the end of the history list. If both arguments are omitted, edit the previous item in the history list.

Shell Commands

cd dir change working directory to dir

pwd print working directory

ls [options] print directory listing

getenv (string) return value of named environment

variable

system (cmd) execute arbitrary shell command string

Matrices

Square brackets delimit literal matrices. Commas separate elements on the same row. Semicolons separate rows. Commas may be replaced by spaces, and semicolons may be replaced by one or more newlines. Elements of a matrix may be arbitrary expressions, assuming all the dimensions agree.

[ x, y, ... ] enter a row vector

[ x; y; ... ] enter a column vector

[ w, x; y, z ] enter a 2×2 matrix

Multi-dimensional Arrays

Multi-dimensional arrays may be created with the cat or reshape commands from two-dimensional sub-matrices.

squeeze (arr) remove singleton dimensions of the array.

ndims (arr) number of dimensions in the array.

permute (arr, p) permute the dimensions of an array.

ipermute (arr, p) array inverse permutation.

shiftdim (arr, s) rotate the array dimensions.

circshift (arr, s) rotate the array elements.

Sparse Matrices

sparse (...) create a sparse matrix.

speye (n) create sparse identify matrix.

sprand (n, m, d) sparse rand matrix of density d.

spdiags (...) sparse generalization of diag.

nnz (s) No. non-zero elements in sparse matrix.

Ranges

base : limit

base : incr : limit

Specify a range of values beginning with base with no elements greater than limit. If it is omitted, the default value of incr is 1. Negative increments are permitted.

Strings and Common Escape Sequences

A string constant consists of a sequence of characters enclosed in either double-quote or single-quote marks. Strings in double- quotes allow the use of the escape sequences below.

\ a literal backslash

" a literal double-quote character

\’ a literal single-quote character

\n newline, ASCII code 10

\t horizontal tab, ASCII code 9

Index Expressions

var (idx) select elements of a vector

var (idx1, idx2) select elements of a matrix

scalar select row (column) corresponding to scalar vector select rows (columns) corresponding to the elements of vector range select rows (columns) corresponding to the elements of range

: select all rows (columns)

Global and Persistent Variables

global var1 ... Declare variables global.

global var1 = val Declare variable global. Set intial value.

persistent var1 Declare a variable as static to a function.

persistent var1 =

val

Declare a variable as static to a function and set its initial value. Global variables may be accessed inside the body of a function without having to be passed in the function parameter list provided they are declared global when used.

Selected Built-in Functions

EDITOR editor to use with edit history

Inf, NaN IEEE infinity, NaN

NA Missing value

PAGER program to use to paginate output

ans last result not explicitly assigned

eps machine precision

pi π

1i

realmax maximum representable value

realmin minimum representable value

Assignment Expressions

var = expr assign expression to variable

var (idx) = expr assign expression to indexed variable

var (idx) = [] delete the indexed elements.

var {idx} = expr assign elements of a cell array.

Arithmetic and Increment Operators

x + y addition

x - y subtraction

x * y matrix multiplication

x .* y element by element multiplication

x / y right division, conceptually equivalent to

(inverse (y’) * x’)’

x ./ y element by element right division

x \ y left division, conceptually equivalent to

inverse (x) * y

x .\ y element by element left division

x ^ y power operator

x .^ y element by element power operator

x negation

+ x unary plus (a no-op)

x ’ complex conjugate transpose

x .’ transpose

++ x (-- x) increment (decrement), return new value

x ++ (x --) increment (decrement), return old value

Comparison and Boolean Operators

These operators work on an element-by-element basis. Both arguments are always evaluated.

x < y true if x is less than y

x <= y true if x is less than or equal to y

x == y true if x is equal to y

x >= y true if x is greater than or equal to y

x > y true if x is greater than y

x != y true if x is not equal to y

x & y true if both x and y are true

x | y true if at least one of x or y is true

! bool true if bool is false

Short-circuit Boolean Operators

Operators evaluate left-to-right. Operands are only evaluated if necessary, stopping once overall truth value can be determined.

Operands are converted to scalars using the all function.

x && y true if both x and y are true

x || y true if at least one of x or y is true

Operator Precedence Table of Octave operators, in order of increasing precedence.

; , statement separators

= assignment, groups left to right

|| && logical “or” and “and”

| & element-wise “or” and “and”

< <= == >= > != relational operators

: colon

+ - addition and subtraction

* / \ .* ./ .\ multiplication and division

’ .’ transpose

+ - ++ --! unary minus, increment, logical “not”

^ .^ exponentiation

Paths and Packages

path display the current Octave cunction path.

pathdef display the default path.

addpath(dir) add a directory to the path.

EXEC PATH manipulate the Octave executable path.

pkg list display installed packages.

pkg load pack Load an installed package.

Cells and Structures

var.field = ... set a field of a structure.

var{idx} = ... set an element of a cell array.

cellfun(f, c) apply a function to elements of cell array.

fieldnames(s) returns the fields of a structure.

Statements

for identifier = expr stmt-list endfor

Execute stmt-list once for each column of expr. The variable identifier is set to the value of the current column during each iteration.

while (condition) stmt-list endwhile

Execute stmt-list while condition is true.

break exit innermost loop

continue go to beginning of innermost loop

return return to calling function

if (condition) if-body [else else-body] endif Execute if-body if condition is true, otherwise execute else- body. if (condition) if-body [elseif (condition) elseif-body] endif Execute if-body if condition is true, otherwise execute the

elseif-body corresponding to the first elseif condition that

is true, otherwise execute else-body.

Any number of elseif clauses may appear in an if

statement.

unwind protect body unwind protect cleanup cleanup end

Execute body. Execute cleanup no matter how control exits body.

try body catch cleanup end

Execute body. Execute cleanup if body fails.

Strings

strcmp (s, t) compare strings

strcat (s, t, ...) concatenate strings

regexp (str, pat) strings matching regular expression

regexprep (str, pat, rep) Match and replace sub-strings

Defining Functions

function [ret-list] function-name [ (arg-list) ] function-body

endfunction

ret-list may be a single identifier or a comma-separated list of identifiers delimited by square-brackets. arg-list is a comma-separated list of identifiers and may be empty.

Function Handles

@func Define a function handle to func.

@(var1, ...) expr Define an anonymous function handle.

str2func (str) Create a function handle from a string.

functions (handle) Return information about a function

handle.

func2str (handle) Return a string representation of a

function handle.

handle (arg1, ...) Evaluate a function handle.

feval (func, arg1,

Evaluate a function handle or string, passing remaining args to func Anonymous function handles take a copy of the variables in the current workspace.

Manual de Octave: Comandos básicos, Apuntes de Arquitectura

Documentos relacionados

Vista previa parcial del texto

¡Descarga Manual de Octave: Comandos básicos y más Apuntes en PDF de Arquitectura solo en Docsity!

Octave Quick Reference Octave Version 3.0.

Starting Octave

octave start interactive Octave session

octave file run Octave on commands in file

octave --eval code Evaluate code using Octave

octave --help describe command line options

Stopping Octave

quit or exit exit Octave

INTERRUPT (e.g. C-c) terminate current command and

Getting Help

help list all commands and built-in variables

help command briefly describe command

doc use Info to browse Octave manual

doc command search for command in Octave manual

lookfor str search for command based on str

Motion in Info

SPC or C-v scroll forward one screenful

DEL or M-v scroll backward one screenful

C-l redraw the display

Node Selection in Info

n select the next node

p select the previous node

u select the ‘up’ node

t select the ‘top’ node

d select the directory node

< select the first node in the current file

> select the last node in the current file

g reads the name of a node and selects it

C-x k kills the current node

Searching in Info

s search for a string

C-s search forward incrementally

C-r search backward incrementally

i search index & go to corresponding node

, go to next match from last ‘i’ command

Command-Line Cursor Motion

C-b move back one character

C-f move forward one character

C-a move to the start of the line

C-e move to the end of the line

M-f move forward a word

M-b move backward a word

C-l clear screen, reprinting current line at top

Inserting or Changing Text

M-TAB insert a tab character

DEL delete character to the left of the cursor

C-d delete character under the cursor

C-v add the next character verbatim

C-t transpose characters at the point

M-t transpose words at the point

[ ] surround optional arguments ... show one or more arguments

Killing and Yanking

C-k kill to the end of the line

C-y yank the most recently killed text

M-d kill to the end of the current word

M-DEL kill the word behind the cursor

M-y rotate the kill ring and yank the new top

Command Completion and History

TAB complete a command or variable name

M-? list possible completions

RET enter the current line

C-p move ‘up’ through the history list

C-n move ‘down’ through the history list

M-< move to the first line in the history

M-> move to the last line in the history

C-r search backward in the history list

C-s search forward in the history list

history [-q] [N ] list N previous history lines, omitting

history numbers if -q

history -w [file] write history to file (~/.octave hist if no

history -r [file] read history from file (~/.octave hist if

edit history lines edit and then run previous commands

run history lines run previous commands from the history

[beg] [end] Specify the first and last history

Shell Commands

cd dir change working directory to dir