Gnuplot filledcurves flip axes - gnuplot

Question

There is a style to fill the space between two functions of x.
Examples of such plots can be found e.g. at http://gnuplot.sourceforge.net/demo/fillbetween.html
Is there any way to make similar plot, but with flipped x and y axes?
Here is the desired shape of a curve (without rotated/mirrored labels, titles and legends, of course)...
It could be done with closed contour (like last example here http://www.gnuplot.info/demo_svg_cvs/fillcrvs.html), but this would require reshuffling the data file. Any other options?
Thank you!

Answer 1

You can't do this directly. From help filledcurves:
The third variant fills the area between two curves sampled at the same set of
x coordinates. It requires three columns of input data (x, y1, y2).
I don't think you can specify (y, x1, x2) directly. As a workaround you can the area between the y axis and the larger function in some color, and then fill the area between the y axis and the smaller function in white:
x1(y) = cos(y)+1
x2(y) = cos(y)+2
xmax(y) = (x1(y) > x2(y) ? x1(y) : x2(y))
xmin(y) = (x1(y) < x2(y) ? x1(y) : x2(y))
plot '+' using (xmax($1)):1 with filledcurve y1, \
'+' using (xmin($1)):1 with filledcurve y1 fillcolor rgb "white"
This probably has to be tweaked a little if one or both of the two functions can be negative.

Answer 2

With gnuplot >=5.2 it could be tweaked even further because it allows arrays.
The following code shows a workaround how filled curves between vertically oriented curves can be realized. You can even use transparency. If you download the attached PNG you will notice that it actually has a transparent background. The basic idea behind this workaround is to make closed areas and fill them. For this, you need to reverse one border, concatenate the borders and plot them filled. Unfortunately, gnuplot has no function to reverse datapoints in a column, so you have to do it in a special procedure yourself.
The code:
### "Vertical" filledcurves
reset session
# create some dummy data
N = 50
set samples N
set xrange [-5:5]
set table $Data
plot '+' u (sin($1)):1:(rand(0)*0.3+1) with table
unset table
# put Borders into arrays
stats $Data nooutput
RowCount = STATS_records
array BorderX1[RowCount]
array BorderX2[RowCount]
array BorderY[RowCount]
set table $Dummy
plot $Data u (BorderX1[$0+1]=$1-$3):(BorderX2[$0+1]=$1+$3):(BorderY[$0+1]=$2) with table
unset table
# reverse BorderX2 and merge borders
set samples RowCount
set table $Border
plot '+' u (BorderX1[$0+1]):(BorderY[$0+1]) with table
plot '+' u (BorderX2[RowCount-$0]):(BorderY[RowCount-$0]) with table
unset table
# make the plot
set object 1 rect at 0,-3 size 10,0.5 fs solid 1.0 fc rgb "black" back
set yrange[-5:5]
plot \
$Border u 1:2 w filledcurves fc rgb "#AA00FF00" not,\
$Border u ($1*1.5):2 w filledcurves fc rgb "#AAFFFF00" not,\
$Data u ($1+2.5):2 w filledcurves y2 fc rgb "brown" not,\
$Data u 1:2 w l lw 8 lc rgb "blue" not,\
'+' u 1:(cos($1)-0.5):(cos($1)+0.5) w filledcurves lc rgb "grey" not,\
'+' u 1:(cos($1)):(1) w l lw 3 dt 2 lc rgb "white" not
### end of code
The result:

Answer 3

Update: These are two alternative and simpler approaches compared to my first answer. One of them works even with gnuplot 5.0.
The plotting style filledcurves (so far) can only fill between two y-curves with identical x-values. However, gnuplot can fill closed curves. So, make the curve closed. Like in my first answer, you can do this if you reverse one curve and add it to the other one.
The assumption for both scripts is that the data has a common y-column, i.e. is organized in 3 columns, e.g. here: y x1 x2
Data: SO50676753.dat (same as OP's data, from silver.dat in the gnuplot demo directory)
# y x1 x2
10 280 16.7332
20 191 13.8203
30 152 12.3288
40 150 12.2474
50 104 10.1980
60 77 8.7750
70 69 8.3066
80 60 7.7460
90 60 7.7460
100 51 7.1414
110 41 6.4031
120 34 5.8310
130 35 5.9161
140 34 5.8310
150 24 4.8990
160 24 4.8990
170 19 4.3589
180 21 4.5826
190 20 4.4721
200 18 4.2426
210 21 4.5826
220 15 3.8730
230 19 4.3589
240 12 3.4641
250 20 4.4721
260 20 4.4721
270 18 4.2426
280 18 4.2426
290 20 4.4721
300 12 3.4641
310 26 5.0990
320 17 4.1231
330 8 2.8284
340 6 2.4495
350 8 2.8284
360 10 3.1623
370 20 4.4721
380 14 3.7417
390 8 2.8284
400 10 3.1623
410 9 3.0000
420 8 2.8284
430 10 3.1623
440 13 3.6056
450 9 3.0000
460 5 2.2361
470 7 2.6458
480 11 3.3166
500 7 2.6458
510 9 3.0000
520 12 3.4641
530 4 2.0000
540 7 2.6458
550 10 3.1623
560 9 3.0000
580 8 2.8284
590 9 3.0000
600 5 2.2361
Script 1: (works with gnuplot>=5.0.0)
Here you assume that you have monotonic and unique y-values. With this you can use the option smooth unique (available at least in gnuplot 4.x versions) to reverse one curve. However, since this solution here uses datablocks and plotting style with table it requires at least gnuplot 5.0.0. Maybe with some workarounds and temporary files you can also get it to work with some 4.6 versions.
### fill between vertical curves
reset session
FILE = "SO50676753.dat"
set table $Temp
plot FILE u 1:2
plot FILE u (-$1):3 smooth unique
set table $Data
plot $Temp u 2:1 index 0 w table, \
'' u 2:(-$1) index 1 w table
unset table
set style fill solid 0.3
set grid x,y
plot $Data u 1:2 w filledcurves
### end of script
Script 2: (works with gnuplot>=5.2.0)
With this solution there are no special assumptions about the data, but since it uses indexing of datablocks it requires gnuplot>=5.2.0.
### fill between vertical curves
reset session
FILE = "SO50676753.dat"
set table $Temp1
plot FILE u 2:1 w table
set table $Temp2
plot FILE u 3:1 w table
unset table
set print $Data
do for [i=1:|$Temp1|] { print $Temp1[i] }
do for [i=|$Temp2|:1:-1] { print $Temp2[i] } # reverse data
set print
set style fill solid 0.3
set grid x,y
plot $Data u 1:2 w filledcurves
### end of script
Result: (same for both scripts):