Re: Suggestion to improve usability of plot command

[Theo H. <th...@ph...>]

Keir Mierle wrote:
> I have a simple suggestion to improve the usability of the plot command.
> Currently, I am not a huge fan of the way point styles are specified; mainly
> because I do not find having to memorize different plot styles as numbers
> remotely intuitive. Also, it is very difficult to tell from the documentation
> exactly how to plot squares or other points instead of crosses (for, i.e.
> overplotting two scatter plots to see where points line up).
> 
> What am I suggesting? Instead of writing:
> 
> gnuplot> plot 'file1' with points 4 3
> gnuplot> plot 'file2' with points 1 4
> 
> I suggest that we support (*in addition* not instead of) two new methods of
> specifying plot styles, one which follows the convention of Matlab and Matplotlib
> (Python's plotting package), and another which is so blatently obvious everyone
> will understand it.
> 
> Note that in the above script, no one could possibly guess what 4 3 or 1 4
> means if they are not a frequent gnuplot user. I actually did not figure out
> that this was the command I was looking for until after several passes through
> the documentation; I erroneously expected the command to be obvious.
> 
> 1) The really obvious version
> -----------------------------
> 
> gnuplot> plot 'file1' with points 'red squares'
> gnuplot> plot 'file2' with points 'blue crosses'
> gnuplot> plot 'file1' with points 'orange octagons'
> gnuplot> plot 'file1' with points 'orange stippled-squares'
> gnuplot> plot 'file1' with points 'violet filled-circles'
[...]

First of all: after reading this thread, I'm surprised no one has 
mentioned the `test` command. From `help plot style`: "If you wish to 
choose the line or point type for a single plot, <line_type> and 
<point_type> may be specified. These are positive integer constants (or 
expressions) that specify the line type and point type to be used for 
the plot. Use `test` to display the types available for your terminal."

The "really obvious" syntax can be implemented using macros. See `help 
macros` for an example. It may be that a single command file containing 
macro definitions may be shared among many terminals (for example, the 
postscript-based ones), although certainly some terminals will demand 
their own macro definitions due to differing line- and point types. Feel 
free to contribute such macro definitions for commonly used terminals.

THeo