problem with "contour"

[Toni Mira <toni.mira@xxxxxx>]

Hi Ferreters,

I would like to draw a variable in 2D, so I am using the contour
command.

My imput data are contained in a ASCII file, which contains three
colums:

X / Y / var

When I execute my script (which is attached) I get the following error
message:

**ERROR: dimensions improperly specified: must be a 2D region
          contour var[g=gaxis]

My questions are:

1) What is wrong in my axes definition?
2) How can avoid the
problem that the values from which the axes are to be created 
    are not in strictly  increasing order ( completely random) ?

Thanks for any help.

Toni


spawn ln -s  retall.dat  retall.copy
file/form=free/var=xx,yy,zz retall.copy
def axis/x/name=xaxis/from_data xx
def axis/y/name=yaxis/from_data yy
list xx,yy
def grid/x=xaxis/y=yaxis gaxis
set grid gaxis
show data

cancel data retall.copy

file/form=free/g=gaxis/var=a,b,var retall.dat	

contour var[g=gaxis]