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

[netCDF #KZG-517636]: NetCDF Python Mask Values Question

Hi Arturo,

I downloaded your dataset and tried playing around with it and was able to 
replicate everything you shared. I do not see anywhere in your subset where the 
mask is False (i.e. there's an actual value there). Outside of the subset (in 
the NDVI array), there are indices were the mask is False. Are you expecting 
data within the subsetted region? More information regarding your issue would 
be helpful!

Best regards,
Zach Bruick

> https://www.ncei.noaa.gov/data/avhrr-land-normalized-difference-vegetation-index/access/2015/AVHRR-Land_v004_AVH13C1_NOAA-19_20150102_c20150730112535.nc
> In the above file many subsets of data appear to be masked but when I convert 
> files using ArcGIS software there are no mask values.
> For example doing the following:
> f = 
> Dataset(r"E:\AVHRR_New\2015\AVHRR-Land_v004_AVH13C1_NOAA-19_20150102_c20150730112535.nc")
> ndvi = f["NDVI"]
> values = ndvi[0,820:823,1150:1153]
> values
> Out[5]:
> masked_array(
> data=[[--, --, --],
> [--, --, --],
> [--, --, --]],
> mask=[[ True,  True,  True],
> [ True,  True,  True],
> [ True,  True,  True]],
> fill_value=-9999,
> dtype=float64)
> However, the same array area in ArcGIS does show values as well as accessing 
> the same in Matlab. Is this a bug in the python library? I had never 
> encountered such an issue.
> Any help would be appreciated

Ticket Details
Ticket ID: KZG-517636
Department: Support Python
Priority: Normal
Status: Open
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.