linuxgnuplot

How to fill curves between different databases in gnuplot?

In gnuplot, when filling the space between two curves, we do:

plot "data" using 1:2,/
     "data" using 1:3,/
     "data" using 1:2:3 with filledcurves,\
    "data2" using 1:2,/
    "data2" using 1:4,/
    "data2" using 1:2:4 with filledcurves

How can I do the same, but with 1:2 of the file "data", but "3" of the file "data2"? Without modifying the databases, of course.

Namely, I want to fill the space between the 2nd column of data and the 4th column of data2. So it would be something like:

plot "data" using 1:2,/
    "data2" using 1:4,/
    ??????????? with filledcurves

EDIT

file data sample:

1736683200  24.28  24.83  1012  79  0.0   12  56
1736694000  24.71  25.09  1011  71  0.0   17  38
1736704800  24.29  24.6   1010  70  0.0   10  53
1736715600  23.6   24.03  1012  77  0.13  7   66
1736726400  23.05  23.47  1011  79  0.32  7   79
1736737200  22.37  22.8   1010  82  0.18  3   88
1736748000  22.15  22.61  1012  84  0.22  4   66
1736758800  22.92  23.36  1012  80  0.49  2   77
1736769600  24.33  24.72  1011  73  0.35  12  41
1736780400  24.62  24.89  1010  67  0.0   15  27
....

file data2 sample:

1736676000  24.6  21.4  1011.8  0  0.0  13.0  85
1736679600  24.9  21.3  1011.6  0  0.0  16.7  83
1736683200  25.2  21.2  1011.4  0  0.0  18.5  74
1736686800  25.2  21.1  1010.9  0  0.0  18.5  76
1736690400  25.2  21.0  1010.3  0  0.0  18.5  78
1736694000  25.2  20.9  1009.8  0  0.0  20.4  82
1736697600  24.7  20.7  1009.8  0  0.0  18.5  82
1736701200  24.2  20.5  1009.7  0  0.0  16.7  83
1736704800  23.7  20.4  1009.7  0  0.0  14.8  83
1736708400  23.6  20.4  1010.3  0  0.0  13.0  85
Solution

  • If you check help filledcurves, you will find the following:

    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).

    This means you can only fill between two curves from the same datafile and shared x-coordinate, but not between two files and different x-coordinates.

    However, there is a workaround:

    Data:

    SO79350012_1.dat

    1736676000  23.6   21.4   1011  0   0.0   13  85 #
1736683200  24.28  24.83  1012  79  0.0   12  56
1736694000  24.71  25.09  1011  71  0.0   17  38
1736704800  24.29  24.6   1010  70  0.0   10  53
1736715600  23.6   24.03  1012  77  0.13  7   66
1736726400  23.05  23.47  1011  79  0.32  7   79
1736737200  22.37  22.8   1010  82  0.18  3   88
1736748000  22.15  22.61  1012  84  0.22  4   66
1736758800  22.92  23.36  1012  80  0.49  2   77
1736769600  24.33  24.72  1011  73  0.35  12  41
1736780400  24.62  24.89  1010  67  0.0   15  27

    SO79350012_2.dat

    1736676000  24.6  21.4  1011.8  0  0.0  13.0  85
1736679600  24.9  21.3  1011.6  0  0.0  16.7  83
1736683200  25.2  21.2  1011.4  0  0.0  18.5  74
1736686800  25.2  21.1  1010.9  0  0.0  18.5  76
1736690400  25.2  21.0  1010.3  0  0.0  18.5  78
1736694000  25.2  20.9  1009.8  0  0.0  20.4  82
1736697600  24.7  20.7  1009.8  0  0.0  18.5  82
1736701200  24.2  20.5  1009.7  0  0.0  16.7  83
1736704800  23.7  20.4  1009.7  0  0.0  14.8  83
1736708400  23.6  20.4  1010.3  0  0.0  13.0  85
1736720000  24.0  20.4  1010.3  0  0.0  13.0  85 #
1736730000  24.6  20.4  1010.3  0  0.0  13.0  85 #
1736750000  24.2  20.4  1010.3  0  0.0  13.0  85 #
1736770000  23.6  20.4  1010.3  0  0.0  13.0  85 #
1736780400  23.9  24.8  1010.1  0  0.0  15.0  27 #

    Script: (requires gnuplot>=5.2.0, because of indexing datablocks)

    ### fill curves between two files
reset session

FILE1 = "SO79350012_1.dat"
FILE2 = "SO79350012_2.dat"

set format x "%Y\n%m-%d\n%H:%M" timedate

set table $Data1
    plot FILE1 u (sprintf("%.0f %g",$1,$2)) w table
set table $Data2
    plot FILE2 u (sprintf("%.0f %g",$1,$2)) w table
unset table

set print $Data
    do for [i=1:|$Data1|]    { print $Data1[i] }
    do for [i=|$Data2|:1:-1] { print $Data2[i] }
unset print

set style fill transparent solid 0.3 noborder
set key noautotitle noenhanced

plot FILE1 u 1:2 w lp pt 7 ti FILE1, \
     FILE2 u 1:2 w lp pt 7 ti FILE2, \
     $Data u 1:2 w filledcurves
### end of script

    Result:

    Output graph