Re: change handling of time data for 5.0?

[Karl R. <ra...@un...>]

On 02.10.2014 19:55, Ethan A Merritt wrote:
> https://sourceforge.net/p/gnuplot/feature-requests/392/
> which points out that it's really annoying if a quantity that represents
> elapsed time is treated as a date rather than simply some number of
> days+hours+minutes+seconds. In that particular use case the
> quantity is a vector length, not an axis coordinate per se,
> so "set xtics time" would not really fill the need. Yes the x coordinate
> is a date, but the vector length is elapsed time - two different formats
> are required.

Right, "date" is a more appropriate name for the option to "set
xtics"/"set format". Later a new option "time" can be introduced,
which checks for the biggest unit in the format string and
consequently does not wrap e.g. at 24hs. Other format string
varieties ("numeral","geographic", ...) can be added as necessary.

For tabular output, "set format <>" could be extended to allow
setting the format for individual column numbers.


> We already broke some backwards compatibility by adding a 2nd
> parameter to
> timecolumn(). The new version obviates the need for "set xdata time" to
> handle input, although arguably it is uglier to put the information
> in the
> "using" part of every plot command rather than setting it only once via
> "set xdata time; set timefmt x 'foo'".

Would it be difficult to make the second parameter to timecolumn()
optional, and use whatever is set via "set timefmt" if no format
string is given?

Alternatively, new command
"set data <coln> [time/numeral/...] <formatstring>" ?


  Karl