merge

2 files changed, 59 insertions, 0 deletions

diff --git a/sys/man/1/fplot b/sys/man/1/fplot
new file mode 100644
index 000000000..73791309c
--- /dev/null
+++ b/sys/man/1/fplot
@@ -0,0 +1,57 @@
+.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.
diff --git a/sys/src/cmd/fplot.c b/sys/src/cmd/fplot.c
index 9d6dd5301..866901135 100644
--- a/sys/src/cmd/fplot.c
+++ b/sys/src/cmd/fplot.c
@@ -57,6 +57,7 @@ void oasin(void) { *sp = asin(*sp); }
 void oacos(void) { *sp = acos(*sp); }
 void oatan(void) { *sp = atan(*sp); }
 void osqrt(void) { *sp = sqrt(*sp); }
+void oexp(void) { *sp = exp(*sp); }
 void olog(void) { *sp = log10(*sp); }
 void oln(void) { *sp = log(*sp); }
 
@@ -79,6 +80,7 @@ struct Operator {
 	"acos",	OUNARY,		0,	50,	oacos,
 	"atan",	OUNARY,		0,	50,	oatan,
 	"sqrt",	OUNARY,		0,	50,	osqrt,
+	"exp",	OUNARY,		0,	50,	oexp,
 	"log",	OUNARY,		0,	50,	olog,
 	"ln",	OUNARY,		0,	50,	oln,
 };