如何在Gnuplot中使用非线性轴？

我看到了一些这样的例子：

f(x) = log10(x)
g(x) = 10**x
set nonlinear x via f(x) inverse g(x)

因此，这一点相当于仅对x进行日志缩放。
但我不明白为什么我们要写反函数？ 我也有这样的情况：

For data in x>=0 range I need to scale x in a way that it shows in an almost-half plot;
For data in -100<=x<0 I need to scale x in a way that it shows in a small part of plot;
For data in x<-100 I need to scale x in a way as for data in x>=0.

对于x>=0范围内的数据，我需要以几乎半幅图的方式缩放x；
对于-100中的数据，forward函数告诉gnuplot在页面上绘制用户坐标[x，y]的位置。称那个位置为[x'，y']。为此，只需要“前进”功能。但交互式终端会回显鼠标位置，并允许您出于各种目的单击绘图。为了知道鼠标点击[x'，y']意味着什么，程序必须将其转换回原来的[x，y]。为此，它需要逆函数

有关在完整绘图的不同部分使用不同缩放函数的示例，请参阅下面复制的在线演示

# This example shows how a nonlinear axis definition can be used to 
# create a "broken axis". X coordinates 0-100 are at the left,
# X coordinates 500-1000 are at the right, there is a small gap between them.
# So long as no data points with (100 < x < 500) are plotted, this works as expected.
#
# f(x) maps x axis (discontinuous) to shadow axis coords (continuous linear range [0:1000])
# g(x) maps shadow axis coords to x axis readout
# 
  set title "A 'broken' x axis can be defined using 'set nonlinear x'"

# Define the broken-axis mapping
  axis_gap = 25.
  f(x) = (x <= 100) ? x : (x < 500) ? NaN : (x - 400 + axis_gap)
  g(x) = (x <= 100) ? x : (x < 100 + axis_gap) ? NaN : (x + 400 - axis_gap)
  set xrange [15:600] noextend
  set nonlinear x via f(x) inverse g(x)

  set xtics 50.
  set xtics rotate by -90 nomirror
  set ytics nomirror
  set border 3
  unset key

# Creation of the broken axis marks (this should be automated)
  set arrow 500 from 100, graph 0 to 500, graph 0 nohead lt 500 lw 2 lc bgnd front
  set arrow 501 from 100, graph 0 length graph  .01 angle 75 nohead lw 2 front
  set arrow 502 from 100, graph 0 length graph -.01 angle 75 nohead lw 2 front
  set arrow 503 from 500, graph 0 length graph  .01 angle 75 nohead lw 2 front
  set arrow 504 from 500, graph 0 length graph -.01 angle 75 nohead lw 2 front

  plot 'silver.dat' with yerrorbars lw 2, '' with lines

#此示例显示如何使用非线性轴定义
#创建一个“断轴”。X坐标0-100位于左侧，
#X坐标500-1000位于右侧，它们之间有一个小间隙。
#只要没有绘制（100# This example shows how a nonlinear axis definition can be used to 
# create a "broken axis". X coordinates 0-100 are at the left,
# X coordinates 500-1000 are at the right, there is a small gap between them.
# So long as no data points with (100 < x < 500) are plotted, this works as expected.
#
# f(x) maps x axis (discontinuous) to shadow axis coords (continuous linear range [0:1000])
# g(x) maps shadow axis coords to x axis readout
# 
  set title "A 'broken' x axis can be defined using 'set nonlinear x'"

# Define the broken-axis mapping
  axis_gap = 25.
  f(x) = (x <= 100) ? x : (x < 500) ? NaN : (x - 400 + axis_gap)
  g(x) = (x <= 100) ? x : (x < 100 + axis_gap) ? NaN : (x + 400 - axis_gap)
  set xrange [15:600] noextend
  set nonlinear x via f(x) inverse g(x)

  set xtics 50.
  set xtics rotate by -90 nomirror
  set ytics nomirror
  set border 3
  unset key

# Creation of the broken axis marks (this should be automated)
  set arrow 500 from 100, graph 0 to 500, graph 0 nohead lt 500 lw 2 lc bgnd front
  set arrow 501 from 100, graph 0 length graph  .01 angle 75 nohead lw 2 front
  set arrow 502 from 100, graph 0 length graph -.01 angle 75 nohead lw 2 front
  set arrow 503 from 500, graph 0 length graph  .01 angle 75 nohead lw 2 front
  set arrow 504 from 500, graph 0 length graph -.01 angle 75 nohead lw 2 front

  plot 'silver.dat' with yerrorbars lw 2, '' with lines