My data files look like this:
我的数据文件如下所示:
c0e0100.dat 0.234
c0e0200.dat 0.857
...
c0e1200.dat 0.003
I would like to extract the x-values from the 4th to 7th character of the filenames in the first column. I tried the following user function:
我想从第一列中的文件名的第4到第7个字符中提取x值。我尝试了以下用户功能:
str2num(s)=(s[4:7]+0.0)
and then:
plot 'file' using (str2num($1)):($2)
but this gives:
但这给了:
internal error: substring range operator applied to non-STRING type
I also tried:
我也尝试过:
plot 'file' using (str2num(stringcolumn($1))):($2)
but got the same result.
但得到了相同的结果。
Is there a way of doing this in gnuplot without running the data through external tools first?
有没有办法在gnuplot中这样做而不先通过外部工具运行数据?
1 个解决方案
#1
The expression $1 is a short cut for column(1), so using $1 already gives you the numerical representation of the respective column. To get the string value, use stringcolumn(1) (without $!), or strcol(1):
表达式$ 1是第(1)列的捷径,因此使用$ 1已经为您提供了相应列的数字表示。要获取字符串值,请使用stringcolumn(1)(不带$!)或strcol(1):
str2num(s)=(s[4:7]+0.0)
plot 'file ' using (str2num(strcol(1))):2
#1
The expression $1 is a short cut for column(1), so using $1 already gives you the numerical representation of the respective column. To get the string value, use stringcolumn(1) (without $!), or strcol(1):
表达式$ 1是第(1)列的捷径,因此使用$ 1已经为您提供了相应列的数字表示。要获取字符串值,请使用stringcolumn(1)(不带$!)或strcol(1):
str2num(s)=(s[4:7]+0.0)
plot 'file ' using (str2num(strcol(1))):2