950717: Multiple Observations; Structures

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: 950717: Multiple Observations; Structures
• From: Unidata Support <support@xxxxxxxxxxxxxxxx>
• Date: Mon, 17 Jul 1995 13:34:14 -0600

>From Roy_Mendelssohn@xxxxxxxxxxxxxxxxxxx Mon Jul 17 03:55:17 1995
>Date: Mon, 17 Jul 1995 08:55:17 EST
>From: "Roy Mendelssohn" <Roy_Mendelssohn@xxxxxxxxxxxxxxxxxxx>
>To: netcdfgroup@xxxxxxxxxxxxxxxx

I know the following two points have been discussed before, but I don't 
remember 
a satisfactory answer and was wondering if anyone had made some progress on 
these fronts.  I am posting this to HDF also, as I am facing similar problems 
there and would appreciate any possible solutions for HDF files also.

1). Some datasets I would like to put into NetCDF/HDF contain multiple 
observations at a given lat, lon,time, depth dimension.  The question is how to 
put these into the format.  One solution suggested is to have the observations 
as the unlimited dimension.  This has several drawbacks.  The first is that the 
dataset can not be expanded along the time axis as more observations are 
obtained.  The second is that the size of the array ends up being dimensioned 
by 
the location with the most number of observations.  This makes the array much 
bigger than it needs to be, often astoundingly so (for example, if there is 
buoy 
data there are a lot of observations, and those locations will set the 
dimensioning for the entire array.

2) Is there any way to create an array of structures, so that at each 
lat,lon,depth,time instead of pointing to a number, I point to a structure?  
This would be helpful when you want to put packed binary records of a fixed 
length into NetCDF.  The length wouldn't be limited by the length of a word on 
the machine (such as if I wanted to have a CMR5 record as the "observation" at 
a 
particular location.

Any help or ideas would be most appreciated.

Roy Mendelssohn
Pacific Fisheries Environmental Group
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097
408-648-9029 (voice and fax)
Roy_Mendelssohn@xxxxxxxxxxxx