有没有办法在gnuplot中绘制一个平均值？

Question

假设我有一个包含两列数据file.dat的文件。 我通常与

plot "file.dat" u 1:2 

我要平均超过10（例如）前点和10点以下绘制它，并绘制其在相同的情节。 我可以轻松地用一些外部脚本，我在那里做另一列：

for(i=-10;i<=10;++i) 
    $3[j] += $2[j-i] 

不过，我想知道做这件事的gnuplot的方式。 我的下一步将是进行高斯平均。

Answer 1

这可能令人惊讶的是，没有内置到gnuplot中。由于gnuplot如何将数据作为流处理，因此没有好的方法来处理gnuplot中的单个数据点以及数据点的范围。

关于gnuplot的一件大事就是调用外部脚本和工具是多么容易。如果你想使用一个外部脚本来处理来自gnuplot的内的数据，你可以做这样的：

plot "<script.py data.dat" u 1:2 

举个例子，你可以用下面的python脚本。这有点矫枉过正，但您可以在脚本或命令行中将参数值设置为硬编码。

#!/usr/bin/python2.7 

import sys 

if (len(sys.argv) > 6): 
print "" 
print "This script takes one mandatory argument, the name of a file containing" 
print "data to be plotted. It takes up to four optional arguments as follows:" 
print " 1) the number of points before a data point to add into average." 
print " 2) the number of points after a data point to add into average." 
print " 3) the column number of y data (first column is column 1)" 
print " 4) the column number of x data (first column is column 1)" 
print "" 
exit() 

# set variable defaults 
box_back = 10 # number of points before current point to add into average 
box_front = 10 # number of points after current point to add into average 
y_col = 2  # column number of y data (first column is column 1) 
x_col = 1  # column number of x data (first column is column 1) 

# assign variables from command line arguments 
inputFileName = str(sys.argv[1]) 
if (len(sys.argv) > 2): 
box_back = int(sys.argv[2]) 
if (len(sys.argv) > 3): 
box_front = int(sys.argv[3]) 
if (len(sys.argv) > 4): 
y_col = int(sys.argv[4]) 
if (len(sys.argv) > 5): 
x_col = int(sys.argv[5]) 

# open input file 
f = open(inputFileName) 

# make list from lines in file 
lines = f.readlines() 

# make sure boxcar average will work 
if ((box_back + box_front + 1) > len(lines)): 
print "" 
print "ERROR: too many points for boxcar averaging." 
print "" 
exit() 

# this is the number of points encompassed in the boxcar average 
num_points = box_back + box_front + 1 

# this variable is the running sum. 
sum_vals = 0 

# add up values for first boxcar average 
for i_ in range(0,num_points): 
sum_vals += float(lines[i_].split()[y_col-1]) 
print float(lines[box_back].split()[x_col-1]),sum_vals/num_points 

# each subsequent average differs only in the first and last points from the 
# previous average. 
for i_ in range(box_back+1,len(lines)-box_front): 
sum_vals += float(lines[i_+box_front].split()[y_col-1]) 
sum_vals -= float(lines[i_-box_back-1].split()[y_col-1]) 
print float(lines[i_].split()[x_col-1]),sum_vals/num_points