On Saturday, 11 May 2013, Ben Elliston wrote:
> After a bit of time to reduce my test case, I've finally worked out
> why I can't get a named column to work in my plotting command. I
> gnuplot> plot 'datafile' every 10::2 using "foo":"bar"
> This errors out with: could not find column with header "foo". The
> data file is definitely correct: row 1 has "foo" and "bar" headings.
> Am I misunderstanding something or is this a bug?
The "every" filter is being applied before processing the input data.
"every 10::2" tells it to skip the first two lines, so the column headers
are explicitly being filtered out of the input stream.
Is it bug? Arguably so. This behaviour was changed as a result of
discussion attached to this bug tracker item #3438848
This change first appeared in release version 4.6.1
When you report a problem, please always provide the version of
gnuplot you are using. In this case it's not clear whether your
version is newer or older than the fix that resulted from that
bug report. Perhaps your version is too old to have the fix, or
perhaps you have found a case that the July 2012 change didn't
cover. If that's the case, please file a new bug report that includes
a set of gnuplot commands that trigger the bug.
Tradition is not the worship of ashes, but the preservation of fire.
- Gustav Mahler