Re: Strange behavior with "++"?

[Ethan A M. <sf...@us...>]

On Wednesday, 07 January, 2015 14:25:53 Philipp K. Janert wrote:
> 
> Consider the following commands:
> 
> set view map
> set isosamples 10
> splot [0:1][0:1] "++" u 1:2:(1) w p
> 
> I would have expected to get a graph
> of 10x10 points on a grid.
> 
> Instead, I get 10 horizontal lines of
> densely packed points.

I thought there had been a discussion of this on gnuplot-beta
with reference to whether it should be changed for version 5.
But now I can't seem to find it. Anyhow, it wasn't changed
and '++' acts just like any other input source to 3D sampling.
  
The x sampling is controlled by "set sample" (default = 100)
The y sampling is controlled by "set isosample" (default = 10)

It says exactly this in the documentation
gnuplot> help special-filenames
 [snip]
 Similarly the pseudo-file '++' returns 2 columns of data forming a regular
 grid of [x,y] coordinates with the number of points along x controlled by
 `set samples` and the number of points along y controlled by `set isosamples`.

 	Ethan


> 
> When I do this:
> 
> set view map
> set isosamples 10
> unset samples
> splot [0:1][0:1] "++" u 1:2:(1) w p
> 
> I get 10 horizontal lines of less
> densely packed points - but still
> no 10x10 grid.
> 
> Am I misunderstanding what "++" does,
> or is this a bug?
> 
> Best,
> 
> 		Ph.