diff --git a/doc/mkgraf.sh b/doc/mkgraf.sh
index 0f26103..c8c1612 100644
--- a/doc/mkgraf.sh
+++ b/doc/mkgraf.sh
@@ -1,13 +1,19 @@
 #!/bin/bash
 
 PI=" 3.141592654 "
-OUT="foo.tex"
+
+OUT="cos01.tex"
 
 gnuplot << __EOF__
 
 set term latex
 set output "$OUT"
 set title "COS01"
+set xlabel "input value"
+
+set ylabel '\rotatebox{90}{corrected value}' 
+
+set grid
 
 plot					\
 	[0:1] [0:1]			\
@@ -16,4 +22,26 @@ plot					\
 
 __EOF__
 
-wc $OUT
\ No newline at end of file
+wc $OUT
+
+OUT="cos010.tex"
+
+gnuplot << __EOF__
+
+set term latex
+set output "$OUT"
+set title "COS010"
+set xlabel "input value"
+
+set ylabel '\rotatebox{90}{corrected value}' 
+
+set grid
+
+plot					\
+	[0:1] [0:1]			\
+	(0.5 - 0.5 * cos(x*$PI*2))	\
+	with line
+
+__EOF__
+
+wc $OUT