⟦6ea284d7f⟧

TextFile

??
?
GNUTEX 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.

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.

Additional help is available for each of these topics:
clear        fig        load       save        substitution
comments     key        manual     set         userdefined
exit         label      plot       shell
expressions  latex      print      startup
?continue
?continuation
?lines
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.
?clear
This 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.
?comments
?comment

Comments:
  Comments are now supported: a # may appear in most places in a line
and gnutex will ignore the rest of the line. It will not have this
affect inside quotes, inside numbers (incl. complex numbers), inside
command substitutions, etc. In short, it works anywhere it makes sense
to work.
?exit
?quit
'exit', 'quit' and your computer's END-OF-FILE character will
exit GnuTeX.  All these commands will clear the output device
(as the 'clear' command does) before exiting.
?expressions
?expression
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 {real,imag}, where <real> and
<imag> must be numerical constants.  For example {3,2} represents 
3 + 2i; {0,1} represents 'i' itself.

Additional help is available for each of these topics:
functions    operators
?functions
?function
?expressions functions
The functions in GnuTeX 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 BASIC sgn()
function is also supported.

Additional help is available for each of these topics:
abs    asin    besj1    ceil    exp    int     real   sinh    tanh
acos   atan    besy0    cos     floor  log     sgn    sqrt
arg    besj0   besy1    cosh    imag   log10   sin    tan
?expressions functions abs
?abs
This 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(arg)**2 + imag(arg)**2) ].
?expressions functions acos
?acos
This function returns the arc cosine (inverse cosine) of its argument.  'acos'
returns its argument in radians. 
?expressions functions arg
?arg
This function returns the phase of a complex number, in radians.  
?expressions functions asin
?asin
This function returns the arc sin (inverse sin) of its argument.  'asin'
returns its argument in radians. 
?expressions functions atan
?atan
This function returns the arc tangent (inverse tangent) of its argument.
'atan' returns its argument in radians. 
?expressions functions besj0
?besj0
This function returns the j0th Bessel function of its argument.  'besj0'
expects its argument to be in radians.
?expressions functions besj1
?besj1
This function returns the j1st Bessel function of its argument.  'besj1'
expects its argument to be in radians.
?expressions functions besy0
?besy0
This function returns the y0th Bessel function of its argument.  'besy0'
expects its argument to be in radians.
?expressions functions besy1
?besy1
This function returns the y1st Bessel function of its argument.  'besy1'
expects its argument to be in radians.
?expressions functions ceil
?ceil
This function returns the largest integer not less than its argument.
For complex numbers, 'ceil' returns the largest integer not less than
the real part of its argument.
?expressions functions cos
?cos
This function returns the cosine of its argument.  'cos' expects its argument
to be in radians. 
?expressions functions cosh
?cosh
This function returns the hyperbolic cosine of its argument.  'cosh' expects
its argument to be in radians. 
?expressions functions exp
?exp
This function returns the exponential function of its argument (e raised to
the power of its argument).
?expressions functions floor
?floor
This function returns the smallest integer not greater than its argument.
For complex numbers, 'floor' returns the smallest integer not greater than
the real part of its argument.
?expressions functions imag
?imag
This function returns the imaginary part of its argument as a real number.
?expressions functions int
?int
This function returns the integer part of its argument, truncated toward
zero.
?expressions functions log
?log
This function returns the natural logarithm (base e) of its argument.
?expressions functions log10
?log10
This function returns the logarithm (base 10) of its argument.
?expressions functions real
?real
This function returns the real part of its argument.
?expressions functions sgn
?sgn
This 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
?sin
This function returns the sine of its argument.  'sin' expects its argument
to be in radians. 
?expressions functions sinh
?sinh
This function returns the hyperbolic sine of its argument.  'sinh' expects
its argument to be in radians. 
?expressions functions sqrt
?sqrt
This function returns the square root of its argument.
?expressions functions tan
?tan
This function returns the tangent of its argument.  'tan' expects its argument
to be in radians. 
?expressions functions tanh
?tanh
This function returns the hyperbolic tangent of its argument.  'tanh' expects
its argument to be in radians. 
?operators
?expressions operators
The operators in GNUTEX 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 FORTRAN **
(exponentiation) operator is also supported.

Parentheses may be used to change order of evaluation.

Additional help is available for each of these topics:
binary    unary
?expressions operators binary
?binary
The following is a list of all the binary operators and their usage:

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

The ternary operator evaluates its first argument (a).  If it is true
(non-zero) the second argument (b) is returned, otherwise the
third argument (c) is returned. 
?expressions operators unary
?unary
The following is a list of all the unary operators and their usage:

Symbol      Example     Explanation
-           -a          unary minus
~           ~a          one's complement
!           !a          logical negation
?fig
Fig is an interactive drawing program that runs on Sun workstations
and under X windows. Files using the Fig language to describe the
pictures can be translated (with a suite of programs in the TransFig
package) to several other languages, such as PostScript, TeX, and
LaTeX.

If you choose the "fig" terminal type in GnuTeX, a Fig format
file is produced that may be edited by Fig, translated by TransFig,
and printed or included in a TeX or LaTeX document. If you have
the EPIC or EEPIC macros, and your dvi translator supports the
tpic \specials, then you have the capability for very
good-quality output that draws curves with lines instead of dots. 
The reader is referred to the Fig and EPIC documentation for further
information. 

On the other hand, the Fig driver does not support user-defined
linestyles, nor the "key" command.

The input file for GnuTeX should contain commands similar to these:
    set terminal fig
    set output "plot.fig"
    set size 5,4
Note that the output file has a ".fig" extension. To obtain EEPIC
output from a command file (called, say, "plot.gnu"), use the
shell commands
	gnutex < plot.gnu
	fig2epic plot.fig plot.tex
Include the file plot.tex in your document as before, along with the
document style options [epic,eepic]. 
?key
LATEX ONLY:

Plotting a Key:
  If you wish a key describing the plots to be made, use the "key" command: 
    key x,y "description1" w <style1> [, "description2" w <style2>"] ...

The key command looks a lot like a plot command. The coordinates x,y
specify the location of the key on the plot (see below).  The key is
drawn as a sequence lines, with one plot described on each line. On
the left-hand side of each line is a representation that attempts to
mimic the way the curve is plotted (eg, a bunch of dots for a line,
the point symbol for a point, etc). On the right side of each line is
the text "description" given in the command. The lines are vertically
arranged so an imaginary straight line divides the left- and
right-hand sides of the key. It is the x-coordinate of this line that
you specify with the x in the key command; the y in the key command is
the bottom of the key.

For example, the plot command
    plot "foo" w points, "bar" w lines, "funky" w linespoints
followed by
    key 5,5 "This is foo" w points, "This is bar" w lines, \
        "This is funky" w linespoints
would give us a key that looks (roughly) like this:
        <> This is foo
    .....  This is bar
    ...+.. This is funky
(The <> is a diamond).

Any styles may be used in the key entries, including user-defined
styles. For the points and linespoints styles, the point type plotted
is determined in the same way as in the plot command, so your key
entries should be in the same order as in the plot command. Note that
a key entry with an empty (ie "") description will not be included in
the key, but may be included to affect the point-type determination.
For example, if you didn't want to key the "foo" curve above, but you
wanted "funky" to look right, the key command is
    key 5,5 "" w points, "This is bar" w lines, \
        "This is funky" w linespoints
and gives us a key that looks (roughly) like this:
    .....  This is bar
    ...+.. This is funky

The key is fairly rough at this time and I may find ways to make it
look better. Suggestions welcome.
?label
IMAGEN, FIG, and LATEX ONLY:

Arbitrary labels may be placed on the most recent plot, using the new
"label" command. The syntax is
    label x,y "text"
where x,y is some coordinate in your plot's coordinate system (the
commas are important). The text is any arbitrary LaTeX input, and will
be processed in LR mode.  The text is centered at the point x,y. The
label command should follow the plot command. Any number of labels may
be placed.

If you want to adjust the way the label is positioned with respect to
the point x,y, add another parameter:
    label x,y "text" pos
where pos is one of r,l,t,b,lt,lb,rt,rb indicating that the text
should be placed so that the point is at the right center, left
center, top center, bottom center, left top corner, etc. 

An arrow can be drawn out from the point simply by giving its
length in problem coordinates, after the pos:
    label x,y "text" pos length
The length is defined to be the HORIZONTAL extent of the arrow, unless
the arrow is vertical, in which case it is the vertical extent of the
arrow.  The arrow is drawn AWAY FROM the text; for example, if pos is
lt, then away is defined to be up and to the left. If it is b, away is
defined to be down. This allows for eight different directions of
arrows.

Further control over the slope of the arrow can be gained by
specifying exactly the slope you want. You should read about vectors
on page 198 in the LaTeX manual. The command looks like
    label x,y "text" pos length, h_slope, v_slope
(the commas are important). The h_slope and v_slope are integers in
the range -4 to 4, which specify the slope of the line (run, rise).
A horizontal line is 1,0, vertical is 0,1. The two numbers may not
have a common divisor other than +1 or -1.

Labels outside of the plotted boundaries are permitted but may
interfere with axes labels or other text; use at your own risk.
?latex
Documentation for the LATEX extensions to gnuplot (gnutex)

To run gnutex at Duke, type
   /usr/local/bin/gnutex
See /usr/local/public/doc/gnutex/* for examples and the manual.

To use the LaTeX facilities of gnutex, the first command to gnutex 
should be 
    set terminal latex
and the output of latex should be directed to a file, for example,
    set output "plot.tex"
This may be anything you like but it should have a ".tex" extension,
of course. Then the size of the plot should be given, eg
    set size 5, 4
tells gnutex to use a 5 inch wide by 4 inch high box for the plot.
This is the size of the actual plotting area; labels (see below) will
extend outside of this size.

When finished, the file will contain all of the plots you have
specified (you probably only want one plot per file). This file can
then be used in a LaTeX document, for example,
    \begin {figure}
           \input{plot}
    \end {figure}
This puts the plot into a figure. 

Other than the above, gnutex acts much as gnuplot used to do. The plot
command will do its usual thing, but since TeX cannot draw straight
lines with arbitrary slopes, and runs out of memory if lines are
approximated by a series of many tiny dots, lines are drawn as a
series of dots. The usual symbols are plotted for the "with points"
linestyle. User-defined styles are also possible.

NOTE: Linestyles may no longer be abbreviated, for example, "p" for
"points", and "l" for "lines". The full word must be written out.

The plot is also labeled in a variety of ways. Get help on topics 
      title     xlabel    ylabel       tics    
      format    key       userstyle    label
      clip
?load
This 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.  

The 'load' command must be the last command on the line. 
        
Syntax:     load <input-file>

The name of the input file must be enclosed in quotes.
?manual
There should be a manual page installed for "gnutex" and for
"lasergnu". There is also a 23-page user manual available, with many
examples. Contact your GnuTeX installer. (At Duke this is found in
/usr/local/public/doc/gnutex/manual/...).
?plot
The 'plot' command is the primary command of the program.  It displays
functions and data in many, many ways.  The full syntax of this
command is:

  plot {ranges}   <function> {style} {, <function> {style}...}

Where <function> is either a mathematical expression or the name of a
data file enclosed in quotes.  User-defined functions and variables may also 
be defined here.

Curly braces {,} denote optional items.

A 'plot' command can be as simple as

   plot sin(x)

or as complex as (!)

   plot [t=1:100] [-pi:pi*2] tan(t), "data.1" with lines, besj0(t) with points

Additional help is available for each of these topics:
datafile    ranges        style
?plot datafile
?datafile
?data
Discrete data contained in a file can displayed by specifying the
name of the data file (enclosed in quotes) on the 'plot' command line.

Data files should contain one data point per line.  A data point may be
specified either as an X and Y value separated by blank space, or as
just the Y value, in which case the program will use the number of the 
coordinate as the X value.  Coordinate numbers starts at 0 and are
incremented for each data point read.  Blank lines and lines beginning
with ! or # will be treated as comments and ignored.


This example compares the data in the file population.dat to a theoretical
curve:
          pop(x) = 103*exp((1965-x)/10)
          plot [1960:1990] 'population.dat', pop(x)

The file population.dat might contain:

! Gnu population in Antarctica since 1965
1965   103
1970   55
1975   34
1980   24
1985   10
?plot ranges
?ranges
?range
These two options specify the region of the plot which will be displayed.

Ranges may be provided on the 'plot' command line as synonyms for the
'set xrange' and 'set yrange' commands.

Syntax:  [{dummy-var =} {xmin : xmax}] { [{ymin : ymax}] }

Where dummy-var is the independent variable ('x' is used by default) and
the min and max terms can be expressions or constants.

Both the min and max terms are optional.  The ':' is also optional if
neither a min nor a max term is specified.  This allows '[]' to be used
as a null range specification.

Specifying a Y range turns autoscaling OFF.

Examples:

plot cos(x)                             ; use current ranges
plot [-10:30] sin(pi*x)/(pi*x)          ; set xrange only
plot [t = -10 :30]  sin(pi*t)/(pi*t)    ; same, but use t as dummy-var
plot [-pi:pi] [-3:3]  tan(x), 1/x       ; set y and xranges
plot [] [-2:sin(5)*-8] sin(x)**besj0(x) ; set only yrange
plot [:200] [-pi:]  exp(sin(x))         ; set xmax and ymin only
?plot style
?style
Plots may be displayed in one of these styles: 'lines', 'points',
'linespoints', 'impulses', or 'dots'.  The 'lines' style connects
adjacent points with lines.  The 'points' style displays a small
symbol at each point.  The 'linespoints' style is a combination of the
previous two styles.  The 'impulses' style displays a vertical line
from the X axis to each point. The 'dots' style is like the 'points'
style except a very tiny dot is plotted at each point, and the symbol
does not vary from plot to plot. This is useful for plotting very many
points to get a feel for the distribution. In addition, for LaTeX
output only, there are user-defined styles (see the 'set style'
command in 'userstyles').

Default styles are chosen with the 'set function style' and 'set data style'
commands.

Syntax:  with <style>

Where <style> is one of 'lines', 'points', 'linespoints', 'impulses',
'dots', or a user-defined style. These keywords may NOT be
abbreviated.

Examples:                              Displays:
plot sin(x) with impulses              ; sin(x) with impulses
plot [-9:30]  sin(x) w points, cos(x)  ; sin(x) with points, cos(x) default
plot [] [-2:5] tan(x), "data.1" with l ; tan(x) default, "data.1" with lines
plot "leastsq.dat" w i                 ; "leastsq.dat" with impulses
?print
This command prints the value of <expression>. 

Syntax:  print <expression>

See 'expressions'.
?save
This command saves either user-defined functions, variables, or both
to the specified file.

Syntax:    save  {option} <filename>

Where <option> is either 'functions' or 'variables'.  If no option
is used GNUTEX saves both functions and variables.

'save'd files are written in text format and may be read by the 
'load' command.

The filename must be enclose in quotes.
?set
?show
The 'set' command sets LOTS of options.

The 'show' command shows their settings.  'show all' shows all the settings.

Additional help is available for each of these topics:
autoscale    logscale    style         variables    ylabel
clip         output      terminal      xlabel       yrange
format       samples     title         xrange       ytics
functions    size        userstyles    xtics        zero
?set autoscale
?show autoscale
?autoscale
Autoscaling is the default for both the x and y axes.  If y
autoscaling is on, the y axis is automatically scaled to fit the range
of the function or data being plotted.  If x autoscaling is on, the x
range is scaled to the data file(s) being plotted; any functions
plotted on the same curve will use the same range. If only functions
are plotted, the current x range is used.

If autoscaling is not on for an axis, the current range for that axis
is used. The current range is the range used for the last plot
command, or defined by the 'set xrange' and 'set yrange' commands, or
[-10:10] initially.
The syntax is
   set autoscale [{axes}]
   set noautoscale [{axes}]
   show autoscale

The optional {axes} parameter specifies the axes affected by the
command. If {axes} is 'x' or 'y', the command affects the x or y axis,
respectively. If {axes} is 'xy', 'yx', or absent, the command affects
both axes.
?set clip
?show clip
?clip
Gnutex normally clips (actually, does not plot at all) data points
that fall within but too close to the boundaries (this is so the large
symbols used for points will not extend outside the boundary lines).
With the user-defined styles of Latex it is often desirable to make
smaller points, and thus points near the boundaries may be plotted. To
turn off clipping, use
    set noclip
To turn it back on, use
    set clip
The default is 'clip'. Without clipping you may have points near the
boundaries that look bad; try adjusting the x and y ranges. Indeed,
for some terminal types this may cause errors.

?set format
?show format
?format
IMAGEN, FIG, and LATEX ONLY:

The format of the tic-mark labels may be set with the "set format"
command. The default format used for both axes is "$%g$", but other
formats such as "%.2f" or "$%3.0f \mu$sec" are often desirable.
Anything accepted by printf when given a DOUBLE-PRECISION number, and
then accepted by LaTeX in LR mode, will work. In particular, the
formats f, e, and g will work, and the d, o, x, c, s, and u formats
will not work. 

Syntax:  set format <axes> "format-string"
         show format

Where <axes> is either 'x', 'y', 'xy', or nothing (which is the same
as 'xy'). The length of the string representing a ticmark (after
formatting with printf) is restricted to 100 characters.
?show functions
The 'show functions' command lists all user-defined functions and their
definitions.

Syntax:  show functions
?set logscale
?show logscale
?logscale
Log scaling may be set on the X and/or Y axis.

Syntax:  set logscale <axes>
         set nologscale
         show logscale

Where <axes> is either 'x', 'y', or 'xy'.
?set output
?show output
?output
By default, plots are displayed to the standard output.  The 'set output'
command redirects the displays to the specified file or device.

Syntax:  set output {filename}
         show output

The filename must be enclosed in quotes.  If the filename is omitted, output
will be sent to the standard output.
?set samples
?show samples
?samples
The sampling rates of functions may be changed by the 'set samples'
command.  By default, sampling is set to 160 points.  A higher sampling
rate will produce more accurate plots, but will take longer.  In generating
plots, GNUTEX will use either the sampling rate set or the resolution of
the current output device, whichever is smaller.

Syntax:  set samples <expression>
         show samples
?set size
?show size
?size
IMAGEN, FIG, and LATEX ONLY:

The 'set size' command will set the size of the plot, in inches.

For example,

    set size 5, 4

tells gnutex to use a 5 inch wide by 4 inch high box for the plot.
This is the size of the actual plotting area; labels (see the 'set
xlabel', 'set ylabel', and 'set title' commands) will extend outside
of this size.
?set style
?show style
?style
Plots may be displayed in one of these styles: 'lines', 'points',
'linespoints', 'impulses', or 'dots'.  The 'lines' style connects
adjacent points with lines.  The 'points' style displays a small
symbol at each point.  The 'linespoints' style is a combination of the
previous two styles.  The 'impulses' style displays a vertical line
from the X axis to each point. The 'dots' style is like the 'points'
style except a very tiny dot is plotted at each point, and the symbol
does not vary from plot to plot. This is useful for plotting very many
points to get a feel for the distribution. In addition, for LaTeX
output only, there are user-defined styles (see the 'set style'
command in 'userstyles').

Default styles are chosen with the 'set function style' and 'set data
style' commands.

Syntax:  set function style <style>
         set data style <style>
         show function style
         show data style

Where <style> is one of 'lines', 'points', 'linespoints', 'impulses',
'dots', or a user-defined style. These keywords may NOT be
abbreviated.

?set terminal
?show terminal
?terminal
GNUTEX supports many different graphics devices.  Use the 'set terminal'
command to select the type of device for which GNUTEX will produce output.

Syntax:  set terminal {terminal-type}
         show terminal

If <terminal-type> is omitted, the program will list the available terminal
types.  <terminal-type> may be abbreviated.

Use 'set output' to redirect this output to a file or device.
?set title
?show title
?title
The plot is labeled in a variety of ways.  A title may be provided for
the plot with 'set title' commands.  The title in effect at the time
of the "plot" command is used, so it should be set before the plot.
Once set, it retains its values until explicitly changed.

For example,

    set title "This is the title"

When not in latex, the title shows up in the upper-left-hand corner of
the plot, whenever the plot is being labeled.

With Latex, this may be more complex:
    set title "This is a very long title\\because it has\\three lines"
?set userstyles
?show userstyles
?userstyles
LATEX ONLY:

  If you find the "dot" approximation to lines to be inadequate, or
desire your different curves on the same plot to have different
styles, then you can define your own style (up to 16 may be defined).
A style may be defined at any time with a command of the form
       set style <name> <point>
or
       set style <name> <spacing> <dot>...
or
       set style <name> <point> <spacing> <dot>...  

The first form defines a style similar to "points", the second similar
to "lines" and the third to "linespoints". The <name> is any
identifier, just as with user-defined variables and functions (it may
not be lines, points, impulses, linespoints, or dots). To use the style,
simply use the <name> where you would use any of the standard
linestyle names: "with <name>", "set data style <name>", or "set
function style <name>".

The <point> is a quoted string of LaTeX source which describes text to
be plotted at each point. Picture-mode and math-mode commands are the
most useful.  For example, "\circle*{100}" draws a disk 1pt in
diameter at each data point (the units of picture coordinates in use
are 1/100 point). "$\Diamond$" produces a large diamond symbol.

The <spacing> and <dot> arguments define a line in terms of a sequence
of "dots" to be output every <spacing> points along the line to be
plotted. <spacing> is a real number whose units are points. Each dot
(up to 5 dots are allowed) is a quoted string of LaTeX text, as with
the point above. The dots are plotted in rotation along the whole
curve. 

Thus, to simulate a linespoints linestyle with alternating big and
little dots every 4 points along the curve but to use a plus sign at
each data point,
       set style mine "$+$" 4 "\circle*{100}" "\circle*{200}"

The default style is as if 
       set style lines 2 "\circle*{1}"
           set style linespoints <varies> 2 "\circle*{1}"
Had been executed. (The smallest circle that will be drawn is about
100 units; smaller sizes as this one will use that smallest size).
Linespoints is special in that its points vary with each curve on the
plot, as with classic gnuplot. This is not possible to embody in a
single user-defined linestyle.

?show variables
The 'show variables' command lists all user-defined variables and their
values.

Syntax:  show variables
?set xlabel
?show xlabel
?xlabel
IMAGEN, FIG, and LATEX ONLY:

The plot is labeled in a variety of ways.  The ticks on the x and y
axes are labeled with the appropriate numbers. The axes may be labeled
and a title provided for the plot with 'set' commands.  The labels
in effect at the time of the "plot" command are used, so they should
be set before the plot. Once set, they retain their values until
explicitly changed. 

To label the x-axis, for example,

    set xlabel "This is the x axis"

This may be more complex:
    set xlabel "This is the $x$ axis\\with more than two\\lines in the label"
Here there are line breaks, and math mode is used to make the 'x' look
like a variable.
?set xrange
?show xrange
?xrange
The 'set xrange' command sets the horizontal range of values which will
be displayed.

This range may also be specified on the 'plot' command line.

Syntax:  set xrange [{xmin : xmax}]

Where <xmin> and <xmax> terms are expressions or constants.

Both the <xmin> and <xmax> terms are optional.
?set ylabel
?show ylabel
?ylabel
IMAGEN, FIG, and LATEX ONLY:

The plot is labeled in a variety of ways.  The ticks on the x and y
axes are labeled with the appropriate numbers. The axes may be labeled
and a title provided for the plot with new 'set' commands.  The labels
in effect at the time of the "plot" command are used, so they should
be set before the plot. Once set, they retain their values until
explicitly changed. 

To label the y-axis, for example,

    set ylabel "This is the y axis"

This may be more complex:
    set ylabel "This is a longer\\version of\\the $y$ axis"
Here there are line breaks, and math mode is used to make the 'y' look
like a variable.

If the ylabel is not coming out quite right (too close to the plot),
its position may be adjusted with a second parameter, such as
    set ylabel "This is the y axis" 2
This will slide the y label about 2 characters further left (away from
the plot). Positive and negative integers are allowed.
?set yrange
?show yrange
?yrange
The 'set yrange' command sets the vertical range of values which will
be displayed.  This command turns autoscaling OFF.

This range may also be specified on the 'plot' command line.

Syntax:  set yrange [{ymin : ymax}]

Where <ymin> and <ymax> terms are expressions or constants.

Both the <ymin> and <ymax> terms are optional.
?set ytics
?set xtics
?noytics
?noxtics
?set noytics
?set noxtics
?ytics
?xtics
?tics
Sometimes the x- or y-axis numbers really don't mean anything, and you
would rather not have the numbers and tics printed on the axis. If
this is the case, insert a
    set noxtics
and/or
    set noytics
before the plot command. To turn them back on use
    set xtics
    set ytics
?set zero
?show zero
?zero
GNUTEX will not display points when their imaginary parts are greater
than the 'zero' threshold.  The default 'zero' value is 1e-8.

Syntax:  set zero <expression>
         show zero
?shell
The 'shell' command spawns an interactive shell.  To return to GNUTEX,
type 'logout' if using VMS, 'exit' or your END-OF-FILE character if
using Unix, or 'exit' if using MS-DOS.

A single shell command may be spawned by preceding it with the ! character
at the beginning of a command line.  Control will return immediately to
GNUTEX after this command is executed.  For example,

    ! dir

prints a directory listing and then returns to GNUTEX.

$ is accepted as a synonym for ! in VMS.
?startup
?.gnutex
When GNUTEX is run, it looks for an initialization file to execute.
This file is called '.gnutex' on Unix systems, and 'GNUTEX.INI' on
other systems.  If this file is not found in the current directory,
the program will look for it in your home directory (under MS-DOS, the
environment variable GNUTEX should contain the name of this
directory).

If this file is found, GNUTEX executes the commands in this file.
This is most useful for setting your terminal type and defining any
functions or variables which you use often.  The variable 'pi' is
already defined for you.
?substitution
Command-line substitution is specified by a system command enclosed in
backquotes (``).   This command is spawned and the output it produces
replaces the name of the command (and backquotes) on the command line.

Newlines in the output produced by the spawned command are replaced with
blanks.

Command-line substitution can be used anywhere on the GNUTEX command line. 

Examples:

a(x) = `leastsq`                ; substitutes "`leastsq`" with output produced
                    by a program named leastsq.
a(x) = `run leastsq.exe`        ; same but for VMS.
?userdefined
?variables
You may define your own functions and variables.  User-defined functions and
variables may be used anywhere. 

User-defined function syntax:
    <function-name> ( <dummy-var> ) =  <expression>

Where <expression> is defined in terms of <dummy-var>.

User-defined variable syntax:
    <variable-name> = <constant-expression>

Examples:
    w = 2
    q = floor(tan(pi/2 - 0.1))
    f(x) = sin(w*x)
    sinc(x) = sin(pi*x)/(pi*x)
    delta(t) = (t == 0)
    ramp(t) = (t > 0) ? t : 0

The variable 'pi' is already defined for you.

See 'show functions' and 'show variables'. See 'latex' for defining
your own linestyles.
DataMuseum.dk

DKUUG/EUUG Conference tapes

⟦6ea284d7f⟧ TextFile

Derivation

TextFile
