未定义的变量:GPVAL_DATA_Y_MIN(Gnuplot) [英] undefined variable: GPVAL_DATA_Y_MIN (Gnuplot)

问题描述

基于此帖子(我正在使用gnuplot gnuplot 4.6补丁程序级别1):

Based on this post (I am using gnuplot gnuplot 4.6 patchlevel 1):

gnuplot:范围内的最大值和最小值

我正在尝试在.pg脚本中使用set yr [GPVAL_DATA_Y_MIN:GPVAL_DATA_Y_MAX]来绘制来自此.dat文件的数据:

I am trying to use set yr [GPVAL_DATA_Y_MIN:GPVAL_DATA_Y_MAX] in my .pg script that plots data from this .dat file:

100 2
200 4
300 9

但是我得到:

undefined variable: GPVAL_DATA_Y_MIN

这是我的脚本:

set terminal png
set output 'img.png'
set xlabel 'x-label'
set ylabel 'y-label'
set boxwidth 0.5
set style fill solid
set yrange [GPVAL_DATA_Y_MIN:GPVAL_DATA_Y_MAX]
plot 'sample.dat' with boxes title ""

有什么想法吗?

推荐答案

gnuplot定义的变量仅在plot命令之后可用(在链接到的问题中，将使用replot重新绘制).

The gnuplot-defined variables are available only after a plot command (In the question you linked to, a replot is used to plot again).

基本上，您有不同的选择:

Basically you have different options:

1. 首先绘制到端子unknown，然后更改为真实端子，设置范围(现在变量可用)，然后replot:

1. First plot to terminal unknown, and then change to the real terminal, set the range (now the variables are available), and replot:

set xlabel 'x-label'
set ylabel 'y-label'
set boxwidth 0.5 relative
set style fill solid

set terminal unknown
plot 'sample.dat' with boxes title ""

set terminal pngcairo
set output 'img.png'
set yrange [GPVAL_DATA_Y_MIN:GPVAL_DATA_Y_MAX]
replot

请注意，我使用的pngcairo终端比png终端提供了更好的结果.我用了set boxwidth 0.5 relative.

Note, that I used the pngcairo terminal, which gives much better results, than the png terminal. And I used set boxwidth 0.5 relative.

使用set autoscale固定范围，而不是设置显式的yrange.您可以使用set offset根据自动缩放的值指定边距:

Use set autoscale to fix the ranges instead of setting an explicit yrange. You can use set offset to specify a margin based on the autoscaled values:

set autoscale yfix
# set offset 0,0,0.5,0.5
plot 'sample.dat' with boxes title ''

使用stats命令提取最小值和最大值:

Use the stats command to extract the minimum and maximum values:

stats 'sample.dat' using 1:2
set yrange[STATS_min_y:STATS_max_y]
plot 'sample.dat' with boxes title ''

这篇关于未定义的变量:GPVAL_DATA_Y_MIN(Gnuplot)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！