# plt - Software for 2D Plots 2.5

File: <base>/plt-2.5a/misc/pltf (1,173 bytes)
``````#! /bin/sh
# file: pltf		G. Moody	24 February 2002

EXP=
XMIN=
XMAX=
DX=
case \$# in
1) EXP="\$1" ;;
2) EXP="\$1"; XMIN=\$2 ;;
3) EXP="\$1"; XMIN=\$2; XMAX=\$3 ;;
4) EXP="\$1"; XMIN=\$2; XMAX=\$3; DX=\$4 ;;
esac

if [ "x\$EXP" = "x" ]
then
cat <<!
This program produces a table of a function of x.  It can understand
all of the normal arithmetic operators (use ^ for "to the power of"
and % for "the remainder of"), parentheses, and a few functions:
s(x)     sine of x (where x is in radians)
c(x)     cosine of x (where x is in radians)
a(x)	   arctangent of x (returns result in radians)
l(x)     natural (base e) logarithm of x
e(x)     exponential of x
j(n,x)   n-th order Bessel function of x (where n is an integer)
sqrt(x)  square root of x (x >= 0

!

echo -n "f(x) = "
echo -n "Enter the minimum value of x [-50]: "
echo -n "Enter the maximum value of x [50]: "
echo -n "Enter the increment of x [1]: "
fi

if [ "x\$XMIN" = "x" ]
then
XMIN=-50
fi
if [ "x\$XMAX" = "x" ]
then
XMAX=50
fi
if [ "x\$DX" = "x" ]
then
DX=1
fi

ftable "\$EXP" \$XMIN \$XMAX \$DX | \
bc -l | \
plt 0 1 -t "f(x) = \$EXP" -x x -y "f(x)"``````