Multiple graphs from a single data set with GNUPlot - graph

Question

I'm attempting to use gnuplot v5.4 to generate multiple graphs from one data set, though using select data from the set per graph.
I generate stats for a small program I'm developing, and write them to a CSV file:
(This CSV format is just what I've made the best progress with - I'm open to changing)
TotalPlayerCount,22
BluePlayerCount,10
RedPlayerCount,12
BluePlayerScoreTotal,50
RedPlayerScoreTotal,60
The following gives me the below graph:
cat <<"EOF" | gnuplot -p
$db <<DB
TotalPlayerCount,22
BluePlayerCount,10
RedPlayerCount,12
BluePlayerScoreTotal,50
RedPlayerScoreTotal,60
DB
set terminal windows size 2000,1000 enhanced font 'Arial,8'
set datafile separator ','
set yrange [0:100]
set boxwidth 0.1 relative
set style fill solid 1.0
plot $db using 2:xticlabel(1) notitle with boxes linestyle 1
EOF
I'm aiming for this:
which I have achieved using this:
cat <<"EOF" | gnuplot -p
$db <<DB
TotalPlayerCount,22
BluePlayerCount,10
RedPlayerCount,12
BluePlayerScoreTotal,50
RedPlayerScoreTotal,60
DB
set terminal windows size 2000,1000 enhanced font 'Arial,8'
set datafile separator ','
set yrange [0:100]
set boxwidth 0.1 relative
set style fill solid 1.0
set multiplot layout 1,2
plot $db using 2:xticlabel(1) every ::1::2 notitle with boxes linestyle 1
plot $db using 2:xticlabel(1) every ::3::4 notitle with boxes linestyle 1
unset multiplot
EOF
Is there a better or more idiomatic way to select from the data file what 'rows' to plot? These indices (in the every clause) work OK, but seem fragile.
I have previously used the trick where a ternary returning undefined in the using will cause gnuplot to ignore that row (e.g. maybe I could use it to select based on string compare) but that doesn't seem much more elegant either and I don't really enjoy how complex it makes the plot command.

Answer 1

One possibility that gives you a more "readable" syntax would be to use columnheaders, for which you would need to transpose your dataset. You don't necessarily need to use comma; spaces or tabs will do the trick as well:
$db <<DB
TotalPlayerCount BluePlayerCount RedPlayerCount BluePlayerScoreTotal RedPlayerScoreTotal
22 10 12 50 60
DB
Set up the layout:
set xrange [0:3]
set yrange [0:100]
set boxwidth 0.5
set style fill solid 1.0
Now you can select the column that you want to plot with column("string"), which will give you the correct y value. As for the x value, I simply took the constant number 1 for the first plot and 2 for the second one. In order to produce xticlabels one has to repeat the string:
plot $db u (1):(column("BluePlayerCount")):xticlabels("BluePlayerCount") w boxes not, \
$db u (2):(column("RedPlayerCount")):xticlabels("RedPlayerCount") w boxes not
Alternatively, you could delete the xticlabels part from the plot command and instead use: set xtics ("BluePlayerCount" 1, "RedPlayerCount" 2)
You could also automate the plot even further:
whattoplot_1 = "BluePlayerCount"
whattoplot_2 = "RedPlayerCount"
x_pos_1 = 1
x_pos_2 = 2
set xtics (whattoplot_1 x_pos_1, whattoplot_2 x_pos_2)
plot $db u (x_pos_1):(column(whattoplot_1)) w boxes not, \
$db u (x_pos_2):(column(whattoplot_2)) w boxes not
Depending on what you want to achieve in the end, you might consider using arrays and iterate over the elements:
array whattoplot[2] = ["BluePlayerCount", "RedPlayerCount"]
plot for [i=1:|whattoplot|] $db u (i):(column(whattoplot[i])) w boxes not
I hope this gives you some inspiration for how to proceed!

Answer 2

If you are flexible with the input data, I would organize it in the following way:
Instead of dumping everything into one file and separating it again, I would create two files, e.g. 'Counts.dat' and 'Scores.dat'.
In the (copy&paste) example below it is included in the code with datablocks $Counts and $Scores, however, if you have your data in files, simply skip the datablocks and in the plot command change it to 'Counts.dat' and 'Scores.dat', respectively.
You don't necessarily need the total count in your data, gnuplot can do this for you.
Furthermore, in the example below I introduced a third column for the color of the boxes. Check the following example as starting point for further optimization.
Code:
### multiplot with boxes and total sum
reset session
$Counts <<EOD
Red 12 0xff0000
Green 5 0x00cc00
Blue 10 0x0000ff
Yellow 7 0xffff00
EOD
$Scores <<EOD
Red 60 0xff0000
Green 30 0x00cc00
Blue 50 0x0000ff
Yellow 80 0xffff00
EOD
set yrange[0:100]
set boxwidth 0.5 relative
set style fill solid 1.0
set key left noautotitle
set grid x,y
set multiplot layout 1,2
set title "Counts"
plot sum=0 $Counts u 0:(sum=sum+column(2),column(2)):3:xtic(1) w boxes lc rgb var, \
keyentry w p ps 0 ti sprintf("Total count: %d",sum)
set title "Scores"
plot $Scores u 0:2:3:xtic(1) w boxes lc rgb var
unset multiplot
### end of code
Result:
Addition: (all data in one datablock or file)
Code:
### multiplot with boxes and total sum in a single file
reset session
$AllInOne <<EOD
# counts
Red 12 0xff0000
Green 5 0x00cc00
Blue 10 0x0000ff
Yellow 7 0xffff00
# scores
Red 60 0xff0000
Green 30 0x00cc00
Blue 50 0x0000ff
Yellow 80 0xffff00
EOD
set yrange[0:100]
set boxwidth 0.5 relative
set style fill solid 1.0
set key left noautotitle
set grid x,y
set multiplot layout 1,2
set title "Counts"
plot sum=0 $AllInOne u 0:(sum=sum+column(2),column(2)):3:xtic(1) index 0 w boxes lc rgb var, \
keyentry w p ps 0 ti sprintf("Total count: %d",sum)
set title "Scores"
plot $AllInOne u 0:2:3:xtic(1) index 1 w boxes lc rgb var
unset multiplot
### end of code