#!/bin/bash
# $Id: dac.gnuplot,v 1.3 2004/04/01 05:36:50 jmuelmen Exp $

DATAFILE=$1
SCRIPT=/tmp/adc.plot
PLOTFILE=${DATAFILE}.ps

if [ ! -e $DATAFILE ] ; then
    exit;
fi

# first fit analog, then digital (because that's how the firmware wants to be
# laid out)
for ADC in 5 3 ; do
PLOTFILE=${DATAFILE}.${ADC}.ps
cat > $SCRIPT <<-"EOF"
Rd = 24.0
Rdd = 8.0
Rset = 39.9
Rt = 62.0
Rv = 10.0
Rw = 6e-2        
vref = 1.24
Rdp(x) = 1 / (1 / Rd + 1 / Rdd) 
Req(a) = 1 / (1 / R(a) + 1 / Rt + 1 / Rset) 
R(a) = (255 - a) * Rv / 256.0 + Rw           
v(a) = vref * (Rdp(1) + Req(a)) / Rdp(1) 
EOF

echo fit v\(x\) \"${DATAFILE}\" using 2:${ADC} via Rd, Rv, Rw 	>> $SCRIPT
echo set terminal postscript color				>> $SCRIPT
echo set output \"$PLOTFILE\"					>> $SCRIPT
echo plot \"${DATAFILE}\" using 2:${ADC}, v\(x\)		>> $SCRIPT

gnuplot $SCRIPT 2>&1 | tail -15

done