Re: Missing/invalid data points in PM3D

[Petr M. <mi...@ph...>]

ad 'help splot datafile':

  Data file organization is essentially the same as for `plot`, except that
  each point is an (x,y,z) triple.  If only a single value is provided, it
  will be used for z, the datablock number will be used for y, and the index
  of the data point in the datablock will be used for x.  If two or four
  values are provided, `gnuplot` uses the last value for calculating the color in
  pm3d plots.  Three values are interpreted as an (x,y,z) triple.  Additional

It seems that in this case of 2 and 4 columns, the last column is the color 
column, and the x and y coordinates are autoindexed.

A trial to improve the docs:

  If two or four values are provided, the last value is used
  for calculating the color in explicit `pm3d` plots.

Further -- what about changed the gnuplot message
gnuplot> splot 't2'
                ^
    2 columns only possible with explicit pm3d style (line 4)


into more user helpful:

    2 columns only possible for 'with pm3d' or 'set pm3d explicit' (line 4)


---
PM