--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plots/myplot	Tue Feb 09 13:44:25 2010 +1030
@@ -0,0 +1,91 @@
+#!/bin/sh
+# 
+# $Id: myplot,v 1.2 2010/01/10 05:06:54 grog Exp $
+#
+# Kludge page to generate plots
+# These may need changing
+STATION=Dereel
+TABLE=observations
+STARTDATE="2009-12-23"
+ENDDATE="2009-12-24"
+COMMON=/home/grog/src/weather/WH-1080/plots/plot-common.gnuplot
+GRAPHFILE=/var/tmp/myplot.foo
+OUTFILE=/home/grog/public_html/weather/myplot.png
+
+# Generate some constants.  
+# Calculate time zone offset from UTC
+# Convert to seconds at UTC
+NOW=`date +%Y%m%d%H%M`
+UTC=`TZ=GMT date -j $NOW +%s`
+# And in local time zone
+LOCAL=`date -j $NOW +%s`
+# The difference is the time zone offset.
+TZOFFSET=`expr $UTC - $LOCAL`
+# Number of seconds in a day
+DAYSECS=86400
+# 2000-1-1 0:0:0 UTC, the gnuplot epoch.  Or so it should be, but for
+# some reason my plots come out offset by 2 hours.  Use GNUFUDGE until
+# I find out why.
+GNUFUDGE=7200
+Y2K=`expr 946684800`
+MY2K=`expr $Y2K + $TZOFFSET + $GNUFUDGE`
+# End of constant generation
+
+# Frob these values
+STARTTIME=`date -j -f "%F %T" "$STARTDATE 0:0:0" +%s`
+# Adjust to gnu epoch
+GNUSTART=`expr $STARTTIME - $Y2K - $TZOFFSET - $GNUFUDGE`
+# midnight on the end day
+ENDTIME=`date -j -f "%F %T" "$ENDDATE 0:0:0" +%s`
+GNUEND=`expr $ENDTIME - $Y2K - $TZOFFSET - $GNUFUDGE`
+# echo  $ENDTIME - $Y2K - $TZOFFSET - $GNUFUDGE
+
+# echo end $ENDTIME start $STARTTIME
+DURATION=`expr $ENDTIME - $STARTTIME`
+# echo DURATION $DURATION
+# Decide how often to place the time ticks. 
+if [ $DURATION -eq $DAYSECS ];  then # single day
+    XTICS=10800 		# 3 hours
+elif [ $DURATION -eq 172800 ]; then   # 2 days
+    XTICS=21600 		# 6 hours
+elif [ $DURATION -le 345600 ]; then # up to 4 days
+    XTICS=43200 		# 6 hours
+elif [ $DURATION -le 864000 ]; then # up to 10 days
+    XTICS=86400 		# 6 hours
+elif [ $DURATION -le 864000 ]; then # up to 10 days
+    XTICS=86400 		# 1 day
+elif [ $DURATION -le 2592000 ]; then # up to 30 days
+    XTICS=172800 		# 2 days
+else				# > 30 days
+    XTICS=`expr $DURATION / 10`	# just hack it
+fi
+
+# echo DATE $STARTDATE ENDDATE $ENDDATE GNUEND $GNUEND DURATION $DURATION XTICS $XTICS
+
+# **************************************************
+# End of setup crap
+# **************************************************
+
+# Do the query
+MY2KP1=`expr $Y2K + $TZOFFSET + $GNUFUDGE - $DAYSECS`
+MY2KM1=`expr $Y2K + $TZOFFSET + $GNUFUDGE + $DAYSECS`
+echo "SELECT unix_timestamp(timestamp(date, time))-$MY2K, outside_temp from $TABLE WHERE station_id = '$STATION' and date >='$STARTDATE' AND date <= '$STARTDATE' ORDER by date, time;" | \
+  mysql weather > $GRAPHFILE.1
+echo "SELECT unix_timestamp(timestamp(date, time))-$MY2KM1, outside_temp from $TABLE WHERE station_id = '$STATION' and date >='$ENDDATE' AND date <= '$ENDDATE' ORDER by date, time;" | \
+  mysql weather > $GRAPHFILE.2
+
+# And the plot
+
+for GRAPHSIZE in "375,250" "1024, 720"; do
+OUTFILE=/home/grog/public_html/weather/myplot.$GRAPHSIZE.png
+
+( cat $COMMON
+cat << EOF
+	set title "Temperature comparison"
+	set ylabel "Temperature (°C)"
+plot "GRAPHFILE.1"  using 1:2  title "23 December"  with lines, \
+     "GRAPHFILE.2"  using 1:2  title "24 December" with lines
+EOF
+) |  sed "s:MIDNIGHT:$GNUSTART:; s:ENDTIME:$GNUEND:; s:GRAPHFILE:$GRAPHFILE:g; s:SIZE:$GRAPHSIZE:; s:OUTFILE:$OUTFILE:; s:SMOOTHED: (smoothed):; s:SMOOTH:smooth bezier:; s:XTICS:$XTICS:" | \
+  gnuplot
+done