shithub: riscv

ref: de19776b2f793de7fdf1111d84d96eb29f9a22fd
dir: /sys/man/1/fplot/

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.TH FPLOT 1
.SH NAME
fplot \- plot elementary function
.SH SYNOPSYS
.B fplot
[
.B -c
[
.B -s
.I size
]] [
.B -r
.I range
]
.I functions ...
.SH DESCRIPTION
.I Fplot
plots elementary
.I functions
separated by spaces. The default output is the screen, but if the
.B -c
option is specified, the plot is written to the standard output as an r8g8b8
.IR image (6).
The latter image size is either 640x480 or the one specified by the
.B -s
option's argument (in the WIDTHxHEIGHT format). The
.B -r
option accepts as argument the x and y ranges, in the format
.LR "xmin:xmax ymin:ymax".
.PP
Each function to be plotted may be a combination of the independent variable x, 
the elementary operations (+, -, *, / and %), and the functions described in
.IR sin (2)
and
.IR exp (2).
The exception being that x^n raises x to the nth power, log is the base 10 logarithm, 
and ln is the natural logarithm.
.SH EXAMPLES
Plot the absolute value and x^3 functions to a 400x400 image(6) on standard output and view with
.IR page (1).
.IP
.EX
fplot -c -s 400x400 'sqrt(x*x)' 'x^3' | page
.EE
.SH SOURCE
.B /sys/src/cmd/fplot.c
.SH SEE ALSO
.IR exp (2),
.IR sin (2),
.IR image (6),
.IR plot (1).
.SH DIAGNOSTICS
.I Fplot
either exits with
.LR "syntax error"
or an empty status.
.SH BUGS
Parentheses after unary operators are not special, e.g. sin(x)/2 is parsed as sin x/2 = sin(x/2) and not (sin x)/2.
.PP
There is no unary plus or minus.
.SH HISTORY
.I Fplot
first appeared in 9front (July, 2011).