?
GNUPLOT is a command-driven interactive function plotting program. It
is case sensitive (commands and function names written in lowercase
are not the same as those written in CAPS). All command names may be
abbreviated, as long as the abbreviation is not ambiguous. Any number
of commands may appear on a line, separated by semicolons (;).
Strings are indicated with quotes. They may be either single or double
quotation marks, e.g.,
load "filename"
cd 'dir'
Any command-line arguments are assumed to be names of files containing
GNUPLOT commands, with the exception of standard X11 arguments, which
are processed first. Each file is loaded with the `load` command, in the
order specified. GNUPLOT exits after the last file is processed. When
no load files are named, gnuplot enters into an interactive mode.
Commands may extend over several input lines, by ending each
line but the last with a backslash (\). The backslash must be the LAST
character on each line. The effect is as if the backslash and newline
were not there. That is, no white space is implied, nor is a comment
terminated. Therefore, commenting out a continued line comments out
the entire command (see `comment`).
In this documentation, curly braces ({}) denote optional arguments to
many commands, and a vertical bar (|) separates mutually exclusive
choices. GNUPLOT keywords or help topics are indicated by backquotes
or `boldface` (where available). Angle brackets (<>) are used to mark
replaceable tokens.
For help on any topic, type `help` followed by the name of the topic.
The new GNUPLOT user should begin by reading about the `plot`
command (type `help plot`).
?cd
The `cd` command changes the working directory.
Syntax:
cd ""
The directory name must be enclosed in quotes.
Examples:
cd 'subdir'
cd ".."
?clear
The `clear` command erases the current screen or output device as
specified by `set output`. This usually generates a formfeed on
hardcopy devices. Use `set terminal` to set the device type.
?line-editing
?editing
?history
The Unix and IBM PC versions of GNUPLOT support command-line editing.
Also, a history mechanism allows previous commands to be edited, and
re-executed. After the command line has been edited, a newline or
carriage return will enter the entire line regardless of where the
cursor is positioned.
The editing commands are as follows:
`Line editing`:
^B moves back a single character.
^F moves forward a single character.
^A moves to the beginning of the line.
^E moves to the end of the line.
^H and DEL delete the previous character.
^D deletes the current character.
^K deletes from current position to the end of line.
^L,^R redraws line in case it gets trashed.
^U deletes the entire line.
^W deletes the last word.
`History`:
^P moves back through history.
^N moves forward through history.
On the IBM PC the use of a TSR program such as DOSEDIT or CED may be
desired for line editing. For such a case GNUPLOT may be compiled with
no line editing capability (default makefile setup). Set READLINE in the
makefile and add readline.obj to the link file if GNUPLOT line editing
is to be used for the IBM PC. The following arrow keys may be used
on the IBM PC version if readline is used:
Left Arrow - same as ^B.
Right Arrow - same as ^F.
Ctl Left Arrow - same as ^A.
Ctl Right Arrow - same as ^E.
Up Arrow - same as ^P.
Down Arrow - same as ^N.
(The readline function in gnuplot is not the same as the readline used
in GNU BASH and GNU EMACS. It is somewhat compatible however.)
?comments
Comments are supported as follows: a # may appear in most places in a line
and GNUPLOT will ignore the rest of the line. It will not have this
effect inside quotes, inside numbers (including complex numbers), inside
command substitutions, etc. In short, it works anywhere it makes sense
to work.
?environment
A number of shell environment variables are understood by GNUPLOT.
None of these are required, but may be useful.
If GNUTERM is defined, it is used as the name of the terminal type to
be used. This overrides any terminal type sensed by GNUPLOT on start
up, but is itself overridden by the .gnuplot (or equivalent) start-up
file (see `start-up`), and of course by later explicit changes.
On Unix, AmigaDOS, and MS-DOS, GNUHELP may be defined to be the pathname
of the HELP file (gnuplot.gih).
On VMS, the symbol GNUPLOT$HELP should be defined as the name of
the help library for GNUPLOT.
On Unix, HOME is used as the name of a directory to search for
a .gnuplot file if none is found in the current directory.
On AmigaDOS and MS-DOS, GNUPLOT is used. On VMS, SYS$LOGIN: is used.
See help start-up.
On Unix, PAGER is used as an output filter for help messages.
On Unix and AmigaDOS, SHELL is used for the `shell` command. On MS-DOS,
COMSPEC is used for the `shell` command.
On AmigaDOS, GNUFONT is used for the screen font. For example:
"setenv GNUFONT sapphire/14".
On MS-DOS, if the BGI interface is used, the variable `BGI` is used to point
to the full path to the BGI drivers directory. Furthermore SVGA is used to
name the Super VGA BGI driver in 800x600 res., and its mode of operation
as 'Name.Mode'.
For example, if the Super VGA driver is C:\TC\BGI\SVGADRV.BGI and mode 3 is
used for 800x600 res., then: 'set BGI=C:\TC\BGI' and 'set SVGA=SVGADRV.3'.
?exit
?quit
The commands `exit` and `quit` and the END-OF-FILE character
will exit GNUPLOT. All these commands will clear the output device
(as the `clear` command does) before exiting.
?expressions
In general, any mathematical expression accepted by C, FORTRAN,
Pascal, or BASIC is valid. The precedence of these operators is
determined by the specifications of the C programming language.
White space (spaces and tabs) is ignored inside expressions.
Complex constants may be expressed as the {,}, where
and must be numerical constants. For example, {3,2}
represents 3 + 2i; {0,1} represents `i` itself. The curly braces
are explicitly required here.
?expressions functions
?functions
The functions in GNUPLOT are the same as the corresponding functions
in the Unix math library, except that all functions accept integer,
real, and complex arguments, unless otherwise noted. The `sgn`
function is also supported, as in BASIC.
?expressions functions abs
?functions abs
?abs
The `abs` function returns the absolute value of its argument. The
returned value is of the same type as the argument.
For complex arguments, abs(x) is defined as the length of x in the
complex plane [i.e., sqrt(real(x)**2 + imag(x)**2) ].
?expressions functions acos
?functions acos
?acos
The `acos` function returns the arc cosine (inverse cosine) of its
argument. `acos` returns its argument in radians.
?expressions functions arg
?functions arg
?arg
The `arg` function returns the phase of a complex number, in radians.
?expressions functions asin
?functions asin
?asin
The `asin` function returns the arc sin (inverse sin) of its argument.
`asin` returns its argument in radians.
?expressions functions atan
?functions atan
?atan
The `atan` function returns the arc tangent (inverse tangent) of its
argument. `atan` returns its argument in radians.
?expressions functions besj0
?functions besj0
?besj0
The `besj0` function returns the j0th Bessel function of its argument.
`besj0` expects its argument to be in radians.
?expressions functions besj1
?functions besj1
?besj1
The `besj1` function returns the j1st Bessel function of its argument.
`besj1` expects its argument to be in radians.
?expressions functions besy0
?functions besy0
?besy0
The `besy0` function returns the y0th Bessel function of its argument.
`besy0` expects its argument to be in radians.
?expressions functions besy1
?functions besy1
?besy1
The `besy1` function returns the y1st Bessel function of its argument.
`besy1` expects its argument to be in radians.
?expressions functions ceil
?functions ceil
?ceil
The `ceil` function returns the smallest integer that is not less than its
argument. For complex numbers, `ceil` returns the smallest integer
not less than the real part of its argument.
?expressions functions cos
?functions cos
?cos
The `cos` function returns the cosine of its argument. `cos` expects its
argument to be in radians.
?expressions functions cosh
?functions cosh
?cosh
The `cosh` function returns the hyperbolic cosine of its argument.
`cosh` expects its argument to be in radians.
?expressions functions exp
?functions exp
?exp
The `exp` function returns the exponential function of its argument
(`e` raised to the power of its argument).
?expressions functions floor
?functions floor
?floor
The `floor` function returns the largest integer not greater than its
argument. For complex numbers, `floor` returns the largest
integer not greater than the real part of its argument.
?expressions functions gamma
?functions gamma
?gamma
The `gamma` function returns the gamma function of the real part of
its argument. For integer n, gamma(n+1) = n! .
If the argument is a complex value, the imaginary component is ignored.
?expressions functions imag
?functions imag
?imag
The `imag` function returns the imaginary part of its argument as a
real number.
?expressions functions int
?functions int
?int
The `int` function returns the integer part of its argument, truncated
toward zero.
?expressions functions log
?functions log
?log
The `log` function returns the natural logarithm (base `e`) of its
argument.
?expressions functions log10
?functions log10
?log10
The `log10` function returns the logarithm (base 10) of its argument.
?expressions functions real
?functions real
?real
The `real` function returns the real part of its argument.
?expressions functions sgn
?functions sgn
?sgn
The `sgn` function returns 1 if its argument is positive, -1 if its
argument is negative, and 0 if its argument is 0. If the argument
is a complex value, the imaginary component is ignored.
?expressions functions sin
?functions sin
?sin
The `sin` function returns the sine of its argument. `sin` expects its
argument to be in radians.
?expressions functions sinh
?functions sinh
?sinh
The `sinh` function returns the hyperbolic sine of its argument. `sinh`
expects its argument to be in radians.
?expressions functions sqrt
?functions sqrt
?sqrt
The `sqrt` function returns the square root of its argument.
?expressions functions tan
?functions tan
?tan
The `tan` function returns the tangent of its argument. `tan` expects
its argument to be in radians.
?expressions functions tanh
?functions tanh
?tanh
The `tanh` function returns the hyperbolic tangent of its argument.
`tanh` expects its argument to be in radians.
?expressions operators
?operators
The operators in GNUPLOT are the same as the corresponding operators
in the C programming language, except that all operators accept
integer, real, and complex arguments, unless otherwise noted.
The ** operator (exponentiation) is supported, as in FORTRAN.
Parentheses may be used to change order of evaluation.
?expressions operators binary
?operators binary
?binary
The following is a list of all the binary operators and their
usages:
Symbol Example Explanation
** a**b exponentiation
* a*b multiplication
/ a/b division
% a%b * modulo
+ a+b addition
- a-b subtraction
== a==b equality
!= a!=b inequality
& a&b * bitwise AND
^ a^b * bitwise exclusive OR
| a|b * bitwise inclusive OR
&& a&&b * logical AND
|| a||b * logical OR
?: a?b:c * ternary operation
(*) Starred explanations indicate that the operator requires
integer arguments.
Logical AND (&&) and OR (||) short-circuit the way they do in C.
That is, the second && operand is not evaluated if the first is
false; the second || operand is not evaluated if the first is true.
The ternary operator evaluates its first argument (a). If it is
true (non-zero) the second argument (b) is evaluated and returned,
otherwise the third argument (c) is evaluated and returned.
?expressions operators unary
?operators unary
?unary
The following is a list of all the unary operators and their
usages:
Symbol Example Explanation
- -a unary minus
~ ~a * one's complement
! !a * logical negation
! a! * factorial
(*) Starred explanations indicate that the operator requires an
integer argument.
The factorial operator returns a real number to allow a greater range.
?help
The `help` command displays on-line help. To specify information on a
particular topic use the syntax:
help {}
If is not specified, a short message is printed about
GNUPLOT. After help for the requested topic is given, help for a
subtopic may be requested by typing its name, extending the help
request. After that subtopic has been printed, the request may be
extended again, or simply pressing return goes back one level to the
previous topic. Eventually, the GNUPLOT command line will return.
?load
The `load` command executes each line of the specified input file as
if it had been typed in interactively. Files created by the `save`
command can later be `load`ed. Any text file containing valid
commands can be created and then executed by the `load` command.
Files being `load`ed may themselves contain `load` commands. See
`comment` for information about comments in commands.
The `load` command must be the last command on the line.
Syntax:
load ""
The name of the input file must be enclosed in quotes.
Examples:
load 'work.gnu'
load "func.dat"
The `load` command is performed implicitly on any file names given as
arguments to GNUPLOT. These are loaded in the order specified, and
then GNUPLOT exits.
?pause
The `pause` command displays any text associated with the command and
then waits a specified amount of time or until the carriage return is
pressed. `pause` is especially useful in conjunction with `load` files.
Syntax:
pause