.TH GRAPH 1
.CT 1 numbers graphics
.SH NAME
graph \- draw a graph
.SH SYNOPSIS
.B graph
[
.I option ...
]
.SH DESCRIPTION
.I Graph
with no options takes pairs of numbers from the
standard input as abscissas
.RI ( x -values)
and ordinates
.RI ( y -values)
of a graph.
Successive points are connected by straight lines.
The graph is encoded on the standard output
for display by
.IR  plot (1)
filters.
.PP
If an ordinate is followed by
a nonnumeric string, that string is printed as a
label beginning on the point.
Labels may be surrounded with quotes
.L
" "
in which case they may be empty or contain blanks
and numbers;
labels never contain newlines.
.PP
The following options are recognized,
each as a separate argument.
.TP
.B  -a
Supply abscissas automatically; no
.IR x -values
appear in the input.
Spacing is given by the next
argument (default 1).
A second optional argument is the starting point for
automatic abscissas (default 0, or 1
with a log scale in
.IR x ,
or the lower limit given by
.BR -x ).
.TP
.B  -b
Break (disconnect) the graph after each label in the input.
.TP
.B  -c
Character string given by next argument
is default label for each point.
.TP
.B  -g
Next argument is grid style,
0 no grid, 1 frame with ticks, 2 full grid (default).
.TP
.B  -l
Next argument is a legend to title the graph.
Grid ranges
are automatically printed as part
of the title unless a
.B -s
option is present.
.TP
.B  -m
Next argument is mode (style)
of connecting lines:
0 disconnected, 1 connected.
Some devices give distinguishable line styles
for other small integers.
Mode \-1 (default) begins with style 1 and
rotates styles for successive curves under option
.BR -o .
.TP
.B -o
(Overlay.)
The ordinates for
.I n
superposed curves appear in the input
with each abscissa value.
The next argument is
.IR n .
.TP
.B  -s
Save screen; no new page for this graph.
.TP
.B -x l
If
.B l
is present,
.IR x -axis
is logarithmic.
Next 1 (or 2) arguments are lower (and upper)
.I x
limits.
Third argument, if present, is grid spacing on
.I x
axis.
Normally these quantities are determined automatically.
.TP
.B -y l
Similarly for
.IR y .
.TP
.B -e
Make automatically determined
.I x
and
.I y
scales equal.
.TP
.B  -h
Next argument is fraction of space for height.
.TP
.B  -w
Similarly for width.
.TP
.B  -r
Next argument is fraction of space to move right before plotting.
.TP
.B  -u
Similarly to move up before plotting.
.TP
.B  -t
Transpose horizontal and vertical axes.
(Option
.B -a
now applies to the vertical axis.)
.PP
If a specified lower limit exceeds the upper limit,
the axis
is reversed.
.SH SOURCE
.B /sys/src/cmd/graph
.SH "SEE ALSO"
.IR plot (1), 
.IR grap (1)
.SH BUGS
Segments that run out of bounds are dropped, not windowed.
Logarithmic axes may not be reversed.
Option
.B -e
actually makes automatic limits, rather than automatic scaling,
equal.