问题
t.dat file looks like this:
260.37
260.04
261.53
261.32
260.19
260.49
260.43
260.59
260.26
260.68
260.28
259.93
260.82
259.50
260.29
260.52
260.30
259.91
262.24
260.58
260.74
260.22
261.66
260.31
260.99
259.79
260.90
259.88
260.19
261.50
259.32
260.79
259.94
260.35
260.03
260.07
261.86
261.09
260.60
260.15
75.17
75.16
75.33
75.31
75.34
75.04
75.49
75.25
75.27
75.32
75.10
75.75
75.58
74.86
75.19
75.44
75.29
75.31
75.55
75.91
75.39
75.65
75.85
75.67
75.62
74.87
75.64
75.69
75.13
77.76
75.31
74.87
75.75
75.27
75.61
74.84
75.72
75.40
74.96
75.33
67.20
67.26
68.15
68.67
68.88
67.56
67.71
66.87
68.74
67.32
66.92
69.62
67.29
66.87
68.33
67.73
68.66
68.75
67.00
67.22
66.93
68.81
67.29
67.18
67.33
67.91
70.34
67.15
68.37
69.60
69.74
69.62
67.33
66.79
67.90
67.39
69.88
68.48
68.96
67.36
47.82
47.54
47.74
47.95
47.65
47.71
47.64
47.71
47.47
48.19
47.82
48.06
47.88
48.22
48.31
47.58
47.41
47.85
47.71
47.93
48.34
47.95
48.70
47.58
47.86
47.96
47.80
48.00
47.51
47.56
47.50
47.52
47.47
47.76
47.53
48.27
47.26
47.79
47.67
47.57
The objective is to print 4 series of histograms, each one separated with spaces, one for each group of every 40 lines. So that histogram group 1 plots data from lines 1:40, second group plots the data from lines 41:80, and so on. So far I've managed to print the first group of histograms separately:
set boxwidth 0.9 relative
set style data histograms
set style fill solid 1.0 border -1
set xtics ("1" 20, "4" 60, "8" 100, "16" 140)
plot 't.dat' using 1 with boxes ls 6 axes x1y1
and print the four groups concatenated:
plot 't.dat' using 1 every ::0::39 with boxes ls 6 axes x1y1
How do I do to plot the other groups in the same plot?
回答1:
Note, that set style data histograms is ignored, because you overwrite it with the with boxes, and boxes and histograms are different ways to plot bar charts from the view point of grouping and arranging the data.
If you can plot the first group with
plot "t.dat" using 0:1 every ::0::39 with boxes
then you can plot the second group with
plot "t.dat" using 0:1 every ::40::79 with boxes
(using 1, like you used is implicitely converted to using 0:1 by gnuplot).
These two plots would overlap because the zeroth column, i.e. the number of the current row only counts the rows which are available after applying the every filter, so in both cases the x-values go from 0 to 39. To have both plotted beneath each other you must add 40 to the second plot (or maybe 41 to have a small gap between the two:
plot "t.dat" using 0:1 every ::0::39 with boxes,\
"" using ($0 + 41):1 every ::40::79 with boxes
Now, to plot all four groups you can either expand this plot command to hold also the other two groups, or you iterate over them with
set boxwidth 0.7 relative
set style fill solid 1.0 noborder
set xtics ("1" 19.5, "4" 60.5, "8" 101.5, "16" 142.5)
unset key
plot for [i=1:4] 't.dat' using ($0+(i-1)*41):1 every ::((i-1)*40)::(i*40-1) with boxes lt i
来源：https://stackoverflow.com/questions/30442964/how-to-plot-histograms-from-rows-in-data-file-gnuplot