From 0c9237e0b461b14656bc8247c7d90b3e20045572 Mon Sep 17 00:00:00 2001
From: iru <devnull@localhost>
Date: Mon, 5 Nov 2012 15:38:39 -0200
Subject: [PATCH 1/3] fplot(1) man page

---
 sys/man/1/fplot | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 sys/man/1/fplot

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.

From c8ea1cd8d7df5c044cf3ac0f29914721093ec0a9 Mon Sep 17 00:00:00 2001
From: iru <devnull@localhost>
Date: Mon, 5 Nov 2012 15:45:10 -0200
Subject: [PATCH 2/3] Add exponential function.

---
 sys/src/cmd/fplot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/src/cmd/fplot.c b/sys/src/cmd/fplot.c
index 9d6dd5301..7a302d733 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 = sqrt(*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,
 };

From 2dbc08a8bc347e9cf9c9291b07b71cf9f00c4acf Mon Sep 17 00:00:00 2001
From: iru <devnull@localhost>
Date: Mon, 5 Nov 2012 15:47:13 -0200
Subject: [PATCH 3/3] Oops, make exponential function work

---
 sys/src/cmd/fplot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/src/cmd/fplot.c b/sys/src/cmd/fplot.c
index 7a302d733..866901135 100644
--- a/sys/src/cmd/fplot.c
+++ b/sys/src/cmd/fplot.c
@@ -57,7 +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 = sqrt(*sp); }
+void oexp(void) { *sp = exp(*sp); }
 void olog(void) { *sp = log10(*sp); }
 void oln(void) { *sp = log(*sp); }