Hi, Lewis!

Panoply uses NetCDF-Java underneath.
The variables you see are constructed by NetCDF-Java.
NetCDF-Java parses StructMetadata.

For Python, which is based on NetCDF-C, you need to parse StructMetadata.0 
string to reconstruct coordinate variables by yourself.
We provide some Python examples at http://hdfeos.org/zoo for handling the 
metadata using netcdf4-python.
For example, you can parse the StructMetadata using Python regular expression 
like below and construct lat/lon

https://raw.githubusercontent.com/hdfeos/zoo_python/master/zoo/lpdaac/myd/MYD17A2_Gpp_1km.py

and visualize it on map.

http://hdfeos.org/zoo/LPDAAC/MYD17A2.A2007073.h09v08.005.2007096132046.hdf.py.png

We'll provide the complete Python LandSat 7 example later at hdfeos.org.


From: Hdf-forum [mailto:[email protected]] On Behalf Of 
Mcgibbney, Lewis J (398M)
Sent: Thursday, December 04, 2014 10:51 AM
To: HDF Users Discussion List
Subject: Re: [Hdf-forum] Extracting Group Variables from Landsat 7 HDF-EOS

Hi,
No it is generated by Panoply [0], however I can see the variable fields when I 
print the Dataset object.
I just can't see how to actually access them cleanly.
I resorted to the following which is horrible, probably inconsistent in it's 
operation across various HDF4 from Landsat 7 and just downright nasty


str(f.__dict__['StructMetadata.0']).split()

This above gives me the StructMetadata.0 element of the dataset dictionary as a 
list. I can then navigate to the index within that list and grab the variable I 
require e.g. UpperLeftPointMtrs

Do you have any better suggestions. I anticipate that this hack will come back 
to bite me pretty soon.
Thank you very much for any information.
lewis

[0] http://www.giss.nasa.gov/tools/panoply/

Dr. Lewis John McGibbney PhD, B.Sc., MAGU
Engineering Applications Software Engineer Level 2
Computer Science for Data Intensive Systems Group 398M
Jet Propulsion Laboratory
California Institute of Technology
4800 Oak Grove Drive
Pasadena, California 91109-8099
Mail Stop : 158-256C
Tel:  (+1) (818)-393-7402
Cell: (+1) (626)-487-3476
Fax:  (+1) (818)-393-1190
Email: [email protected]<mailto:[email protected]>

           [cid:[email protected]]

 Dare Mighty Things

From: "H. Joe Lee" <[email protected]<mailto:[email protected]>>
Reply-To: HDF Users Discussion List 
<[email protected]<mailto:[email protected]>>
Date: Thursday, December 4, 2014 at 7:09 AM
To: HDF Users Discussion List 
<[email protected]<mailto:[email protected]>>
Subject: Re: [Hdf-forum] Extracting Group Variables from Landsat 7 HDF-EOS

Hi, Lewis!

 Is screen shot generated from ToolsUI (Netcdf-Java)?



--
Save the Earth. Save Earth data in HDF-EOS. Save Big data in HDF.

On Wed, Dec 3, 2014 at 4:40 PM, Mcgibbney, Lewis J (398M) 
<[email protected]<mailto:[email protected]>> wrote:
Hi Folks,
I am really struggling to extract certain Group variables from a HDF4 hdf-eos 
Landsat 7 file.
I am using the netcdf4-python driver [0] in order to achieve this task. I've 
installed the chain of dependencies fine.
The Group Variables which I cannot seem to access are included within the 
attached .png. E.g. Projection, UpperLeftPointMtrs, LowerRightMtrs and 
SphereCode.
I can however view them when I read in the HDF4 file as follows


f = Dataset(hdfFile)

print f

<output>
...

GROUP=GridStructure

GROUP=GRID_1

GridName="Grid"

XDim=8001

YDim=7271

UpperLeftPointMtrs=(310185.000000,4575015.000000)

LowerRightMtrs=(550215.000000,4356885.000000)
...
</output>

Can someone please advise me as how I can extract the Group Variables as I've 
explained above?
Thank you very much in advance for any assistance.
Best
Lewis

[0] http://unidata.github.io/netcdf4-python/


Dr. Lewis John McGibbney PhD, B.Sc., MAGU
Engineering Applications Software Engineer Level 2
Computer Science for Data Intensive Systems Group 398M
Jet Propulsion Laboratory
California Institute of Technology
4800 Oak Grove Drive
Pasadena, California 91109-8099
Mail Stop : 158-256C
Tel:  (+1) (818)-393-7402<tel:%28%2B1%29%20%28818%29-393-7402>
Cell: (+1) (626)-487-3476<tel:%28%2B1%29%20%28626%29-487-3476>
Fax:  (+1) (818)-393-1190<tel:%28%2B1%29%20%28818%29-393-1190>
Email: [email protected]<mailto:[email protected]>

           [cid:[email protected]]

 Dare Mighty Things

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