[Gnuplot-info] filledcurves with gradient fill?

[Mikhail K. <mko...@gm...>]

Hi all.

Does anyone by a chance knows a less crude way to get a dataset plotted 
as "filledcurves" with gradient fill, other than used by me?

My code and the plot are attached. With my code only one dataset is 
possible obviously, and i would like to be able plot more than one.

thank you,
Mikhail

set term pngcairo enhanced font "Helvetica,12" size 500,200
set datafile separator "\t"

set xdata time
set timefmt "%b %d, %Y %H:%M"
set xrange ["Oct 27, 2012 00:00" to "Nov 27, 2012 00:00"]
set format x "%b %d"

set table
set output "/dev/null"
set timefmt "%Y-%m-%d %H:%M:%SZ"
plot \
   "Loven_Wind_data.txt" \
   using 1:6
unset table

X_MAX=GPVAL_X_MAX
X_MIN=GPVAL_X_MIN
DATA_X_MAX=GPVAL_DATA_X_MAX
DATA_X_MIN=GPVAL_DATA_X_MIN

set output "TEST01-10-sensor_data-11-temperature.png"

set lmargin at screen 0.1
set rmargin at screen 0.95
set tmargin at screen 0.90
set bmargin at screen 0.10

A = -20
B = 25
set yrange [A to B]

set multiplot

unset ytics
unset y2tics
unset xtics
set key off

set pm3d map
set palette defined ( -20.0 "black", -5.0 "blue", 0.0 "white", 10.0 
"red", 25.0 "black" )
unset colorbox
set isosamples 200
splot y notitle
unset pm3d

if (X_MAX>DATA_X_MAX) \
   set timefmt "%s"; \
   set object 1 rectangle from DATA_X_MAX, graph 0 to graph 1, graph 1 
fc rgb "white" fs solid 1.0 border; \
   plot 0/0 notitle; \
   unset object 1
if (X_MIN<DATA_X_MIN) \
   set timefmt "%s"; \
   set object 1 rectangle from graph 0, graph 0 to DATA_X_MIN, graph 1 
fc rgb "white" fs solid 1.0 border; \
   plot 0/0 notitle; \
   unset object 1

set timefmt "%Y-%m-%d %H:%M:%S"
plot \
   "Loven_Wind_data.txt" \
       using 1:($5>0 ? $5 : 0):(25) w filledcurves below fc rgb "white" 
notitle, \
   ""  using 1:($5<=0 ? $ 5 : 0):(-20) w filledcurves above fc rgb 
"white" notitle

set ylabel "Air temperature, C"
set border
set ytics -20,10
set xtics
set grid
plot \
   "Loven_Wind_data.txt" \
   using 1:5 w l lt -1 notitle

unset multiplot
unset output