Re: problem in using ferret

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Zhi,
1 - There are a number of "reserved names" in Ferret that have special 
meanings, like X and Y.  You can still use them if they're in a netCDF 
file, by putting them in single-quotes

  yes? shade 'x'

You can find the discussion of this in the Users Guide, by looking in 
the index under "netCDF, variables, invalid names, or variable, names in 
netCDF file".

2 - This turns out to be a due to a bug, which we found and fixed in the 
most recent version of Ferret, v5.80. SHADE and POLYGON plots did not 
get the levels correctly set when there is just one level, although the 
colorbar is correct.  The value of dy in your dataset is 111194.93 and 
an internal loss of precision  meant the level was not set correctly.  
If you can upgrade to Ferret v5.80 this will be fixed.  (try "shade dy - 
111194.93").

Ansley

Zhi Liang wrote:

> Hi,
>
>    I generated a netcdf grid file and I found two problems when I use 
> ferret shade command.
>
> 1.  I use variable name "x" and "y" to represent the grid location 
> along i and j-direction.
>     When I try to do shade x ( or y) in ferret, I got the following  
> error message ( I tried on different system),
>
> **ERROR: dimensions improperly specified: 9999999 words were requested.
> *** NOTE: Check for unspecified limits on an ABSTRACT axis
> *** NOTE: Use the SHOW GRID command to see the axes
>
>   After rename "x" to "x_T" or something else, it works fine. This 
> looks like the ferret can
>   not deal with variable with name "x" or "y" ("x" and "y" are 
> reserved in ferret?).  We want
>   to use the general variable "x" and "y" and do not want to rename 
> these variables.
> 2.  There is another variable dy in the grid file. dy is constant for 
> all the points. When I do shade dy,
>     it has no error message, but the drawing window is empty ( no 
> constant graph) .
>
> I attached a simple grid file in the email for testing purpose and the 
> ferret version I am
> using is FERRET v5.70.  Could anyone provide some solutions or 
> suggestions?
>
>  Thank you very much!
>
> Zhi