Re: timefmt specifier

[Ethan M. <merritt@u.washington.edu>]

On Saturday 27 March 2010, pl...@pi... wrote:
> Hi,
> 
> I have an additional problem/suggestion relating to a similar set of data
> 
> F-00238    378  700323-700330     511.0  -28.8    516.6    11
> 
> the date (range) is contained in $3 this one being 23rd March 1970 - 
> 30th March 1970
> 
> Unless I have missed a trick it does not seem possible to read this in 
> with gnuplot (more awking required?)

I have never figured out how to use gnuplot's builtin time/date routines
effectively.  I suggest you read in the relevant field of the input file
as a string or a pure integer and do the date formatting yourself
using strptime()/strftime(). 

> What would be useful is a dead text specifier. The useful data matches 
> %y%m%d but I can't tell it to ignore the rest.
> 
> A new specifier like %i to ignore the rest of the string would be useful 
> (and easy to add ).
> 
>   "%y%m%d-%i"
> 
> Have I missed an easy way to handle this?

See above. Read it as a string and chop it into the pieces you need.

 mystartdate(i) = strcol(i)[5:6]."-".strcol(i)[3:4]."-19".strcol(i)[1:2]

plot foo using  (mystartdate(3)): ....

will turn your 700323-700330 into "23-03-1970", which you can now do with
whatever you like.  Of course this particular function forces all your
dates into C20.  You'd need a more complicated function to match a 
different convention of input dates. 

	Ethan



	Ethan