[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[netCDF #SOG-600983]: CDO finding min variable value over multiple files



Hi Justin,

To make sure I understand; you want to find the minimum point for each x/y pair 
for a data set (spread between 5 files) and generate a new netCDF file which 
contains the data associated with that minimum.  Is this correct? The netCDF 
library doesn't have any core utility that will help speed this along, 
unfortunately.  I'm not certain how we would do this with CDO or NCO either; my 
go-to would be to suggest netcdf4-python, but you've ruled that out.  How large 
are the individual files?  I assume they must be quite large if the numpy 
overhead is enough to rule out that approach. 

I've given this some thought and short of writing a program in C to do this, 
and assuming the files are too large to dump to CDL or another text format to 
parse *that* way, I'm afraid I'm at a bit of a loss as to how we could approach 
this without reverting to something like Python.  Let me take a look at the 
CDO/NCO documentation and see if I can find an approach that might work.  

-Ward

> Hi team,
> 
> I had a question about how to approach finding the min value for a variable
> over all x/y dimensions over 5 files.
> 
> I'm trying to take 5 netCDF files with identical shapes (x,y,variable) and
> for each x/y I want to find the minimum value of the variable at a
> particular x/y from all 5 seats and make a new netCDF file such that at
> every x/y the new file will have the minimum of the 5 sets. Hope that makes
> sense.
> 
> I’m familiar with the basic commands of CDO and NCO, but I don’t know how I
> would attempt this operation. I can do it Python, but the time and
> computation with numpy is not viable right now.
> 
> Any insight would be much appreciated, thanks
> 
> Justin Richling
> 
> 


Ticket Details
===================
Ticket ID: SOG-600983
Department: Support netCDF
Priority: Normal
Status: Closed
===================
NOTE: All email exchanges with Unidata User Support are recorded in the Unidata 
inquiry tracking system and then made publicly available through the web.  If 
you do not want to have your interactions made available in this way, you must 
let us know in each email you send to us.