这需要多走几步，最重要的是，每个类别都被赋予一个唯一的索引号，并且数据被转置：
（这里我会参考 GNU unix shell 命令）
$cat -n data_orig.dat | datamash transpose > data_trans.dat
$cat data_trans.dat #added spaces for readability
1 2 3 4 5 6
cat dog bat rat foo bar
0.26 0.317 0.33 0.59 0.59 0.664
0.4 0.264 0.42 0.62 0.67 0.75
0.23 0.25 0.32 0.57 0.71 0.68
0.16 0.26 0.48 0.56 0.70 0.6
现在可以按列正确分析数据，并根据索引号定义颜色。
条形图由箭头组成，其中最小值和最大值取自每列的统计分析。
通过系统调用将xticlabels 读入一维word 数组（这是一个内部gnuplot 函数），并使数组索引与数据列的唯一索引匹配。
脚本有非常详细的解释，以更好地支持新的 gnuplot 用户：
#output and style settings: make png-file, name it 'animals.png',
# yaxis tics on both sides, no legend
set terminal png
set output 'animals.png'
set ytics mirror
unset key
#data indices are integers from 1 to 6, a bit of space for the looks
set xrange [0.5:6.5]
#define color scheme for each data series
set palette defined ( 0 'purple', 1 'blue', 2 'green', \
3 'yellow', 4 'orange', 5 'red' , 6 'black' )
#hide color gradient bar of palette
unset colorbox
#define array names using word function:
# read in 2nd line of data by system call and run through words
# each space-delimited word is now an array element of names
names(n) = word( system("sed -n '2p' cat.dat_t" ) , n )
#create min->max bars
#loop over all data sets to create bars
do for [i=1:6] {
#among others this gives minimum and maximum values of the data set
#using i -> only handle column i in statistics
#every ::3 start with row 3 for statistical analysis
stats 'data_trans.dat' using i every ::3
#use min/max values for arrow y positions, index i for x positions
#heads = arrow head on both sides
#size 0.1,90 = 0.1 line lengths for arrow head
# and 90° arrow head line angles = T bar style
#lc palette cb i = use line color (lc) from palette value matching
# color bar (cb) value of index i
set arrow from i,STATS_min to i,STATS_max heads size 0.1,90 lc palette cb i
}
#plotting:
# for [i=1:6] loop over all 6 columns, use i as loop variable
# every ::3 start with row 3 for data plotting
# using (i):i:(i):xtic(names(i))
# syntax of using
# x-value:y-value:z-value:label_x_axis [:label_y_axis:label_z_axis]
# (i) -> literal value of i for x and z, z is used as color definition
# i -> y-values from column i
# xtic(names(i)) get element i of array names for xtic label
# lc palette -> coloring according to defined palette
# pt 7 ps 1.5 -> point style and size definition
plot for [i=1:6] 'data_trans.dat' every ::3 using (i):i:(i):xtic(names(i)) lc palette pt 7 ps 1.5
参考资料：
coloring based on x-values
array from word function
结果：
编辑：
如@theozh 的答案所示，linespoints 显示范围更为实用。这允许通过在绘图命令行中添加w lp 来跳过整个条形/箭头创建块。