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

[IDV #LPW-471935]: Plotting .hdf files in IDV



Alexa,

I think I know what the problem is, but don't have time to try before I go home.

I think the problem is that we have only changed one variable when we should
have changed them all, at least all those that are listed under the Field
Selector.  The IDV may be getting confused on this.

Do you want to give that a shot and let me know what happens?

Best,

Unidata IDV Support

> Alexa,
> 
> Yes, thanks for the clarification. (I think the ordering of our messages got
> jumbled there.)
> 
> I see what you are saying, and when I load each individual file separately I 
> can
> see the data are definitely not the same so something is amiss. We'll resume
> tomorrow.
> 
> Best,
> 
> Unidata IDV Support
> 
> > Hi there â thank you for for your reply. Using your syntax below, I tried 
> > aggregating three files (edited script attached) â different files this 
> > time. Again, the files are read into IDV with the correct time stamps, and 
> > I can toggle between the times, but the strange thing is the plot does not 
> > change with time. Itâs like itâs only plotting one time. -Alexa
> >
> >
> >
> >
> >
> > > On Mar 31, 2016, at 3:46 PM, Unidata IDV Support <address@hidden> wrote:
> > >
> > > Alexa,
> > >
> > > Great! Glad we are making progress and also that you are hanging in 
> > > there. This
> > > stuff is not so easy.
> > >
> > > Replace the current values element with something like this:
> > >
> > >   <values>0 3 11</values>
> > >
> > > But if that is too onerous because you have many file, we will have to go 
> > > via
> > > the time extraction route. Let me know...
> > >
> > > Best,
> > >
> > > Unidata IDV Support
> > >
> > >> Hello â this looks great, and I appreciate your help with this. Your 
> > >> ncml script worked for the two test files and the times look right. 
> > >> However, since we have some missing satellite images, not all the files 
> > >> are spaced exactly 10 mins apart. Is there a way to specify time gaps 
> > >> between individual files begin aggregated? Otherwise, perhaps extracting 
> > >> the time from the file name would be good route. -Alexa
> > >>
> > >>
> > >>> On Mar 31, 2016, at 3:29 PM, Unidata IDV Support <address@hidden> wrote:
> > >>>
> > >>> Hi again,
> > >>>
> > >>> The embedded NcML is a bit hard to read so attached, you will find
> > >>> that same NcML file.
> > >>>
> > >>> Best,
> > >>>
> > >>> Unidata IDV Support
> > >>>
> > >>>> Hi Alexa,
> > >>>>
> > >>>> It is a little tricky but you can fix these problems with a bit of
> > >>>> NcML. To get us going, let's look at the following NcML which can be
> > >>>> read into the IDV and will allow you to view the
> > >>>> `channel_14_brightness_temperature' over time. This file should be
> > >>>> located next to your `hdf' files. Please read the comments in the NcML
> > >>>> for more information about what is going on here.
> > >>>>
> > >>>> ,----
> > >>>> | <?xml version="1.0" encoding="UTF-8"?>
> > >>>> | <netcdf 
> > >>>> xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
> > >>>> |   <!-- Create a time coordinate variable that will be used for the 
> > >>>> aggregation. -->
> > >>>> |   <variable name="time" type="int" shape="time" >
> > >>>> |     <!-- Let's add some units. Alexa: please make sure these units 
> > >>>> are correct. -->
> > >>>> |     <attribute name="units" value="minutes since 2014-04-04 19:09"/>
> > >>>> |     <!-- Specify this variable as a time coordinate -->
> > >>>> |     <attribute name="_CoordinateAxisType" value="Time" />
> > >>>> |     <!-- Increment each file listed below by 10 minutes. Alexa, 
> > >>>> please make sure this -->
> > >>>> |     <!-- assumption about the times is correct. -->
> > >>>> |     <values start="0" increment="10" />
> > >>>> |   </variable>
> > >>>> |   <!--   Specify the coordinates of time lat lon for this one 
> > >>>> variable. Please use -->
> > >>>> |   <!-- this as an example for other variables you are interersted 
> > >>>> in. In other -->
> > >>>> |   <!-- words, you can copy and paste this variable NcML element for 
> > >>>> your other -->
> > >>>> |   <!-- variables. -->
> > >>>> |   <variable name="channel_14_brightness_temperature" shape="lines 
> > >>>> elements" type="short">
> > >>>> |     <attribute name="coordinates" value="time pixel_latitude 
> > >>>> pixel_longitude" />
> > >>>> |   </variable>
> > >>>> |   <!-- Now you are ready to do your aggregation, which is the easy 
> > >>>> part at this point -->
> > >>>> |   <aggregation dimName="time" type="joinNew">
> > >>>> |     <variableAgg name="T"/>
> > >>>> |     <netcdf location="geocatL1.MTSAT-1R.2014044.190900.hdf"/>
> > >>>> |     <netcdf location="geocatL1.MTSAT-1R.2014044.191900.hdf"/>
> > >>>> |   </aggregation>
> > >>>> | </netcdf>
> > >>>> `----
> > >>>>
> > >>>> In summary, this NcML should aggregate over time the two of HDF files
> > >>>> you provided. You will see only one variable that is aggregated over
> > >>>> time; `channel_14_brightness_temperature'.  I'll leave it up to you to
> > >>>> do the others though do not hesitate to ask for help.
> > >>>>
> > >>>> Also, if interested, there are also fancier tricks we can do here such
> > >>>> as NcML can be smart enough to extract the times from the file names.
> > >>>>
> > >>>> Best,
> > >>>>
> > >>>> Unidata IDV Support
> > >>>>
> > >>>>> Ok sounds promising. Here is the link to another file, which should 
> > >>>>> differ only in time â 
> > >>>>> https://drive.google.com/file/d/0B1jVlP9ZfAZCRDVyczU3N2NMbFU/view?usp=sharing
> > >>>>>    -Alexa
> > >>>>>
> > >>>>>> On Mar 30, 2016, at 4:49 PM, Unidata IDV Support <address@hidden> 
> > >>>>>> wrote:
> > >>>>>>
> > >>>>>> Alexa,
> > >>>>>>
> > >>>>>> Indeed we may be able to patch things up with a bit of ncml. I only 
> > >>>>>> found one
> > >>>>>> file at the drive.google location. Would it be possible to see more 
> > >>>>>> so that we
> > >>>>>> have something to aggregate?
> > >>>>>>
> > >>>>>> Best,
> > >>>>>>
> > >>>>>> Unidata IDV Support
> > >>>>>>
> > >>>>>>> Hello IDV Support,
> > >>>>>>>
> > >>>>>>> I am working on reading in a number of HDF files using âaggregate 
> > >>>>>>> grids by timeâ or similar. I am able to read the files in 
> > >>>>>>> individually without a problem, but it looks like the time variable 
> > >>>>>>> is not recognized. The error message is "Grid data source failed 
> > >>>>>>> making data setâ.Dimension time does not existâ. Any ideas for 
> > >>>>>>> how to specify the time variable? Could this be achieved with an 
> > >>>>>>> .ncml script?
> > >>>>>>>
> > >>>>>>> Example file is located here: 
> > >>>>>>> https://drive.google.com/file/d/0B1jVlP9ZfAZCRFhkRVM2aVVRVGc/view?usp=sharing
> > >>>>>>>
> > >>>>>>> All the best
> > >>>>>>>
> > >>>>>>> Alexa
> > >>>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>> Ticket Details
> > >>>>>> ===================
> > >>>>>> Ticket ID: LPW-471935
> > >>>>>> Department: Support IDV
> > >>>>>> Priority: Normal
> > >>>>>> Status: Closed
> > >>>>>>
> > >>>>>
> > >>>>>
> > >>>>
> > >>>
> > >>>
> > >>> Ticket Details
> > >>> ===================
> > >>> Ticket ID: LPW-471935
> > >>> Department: Support IDV
> > >>> Priority: Normal
> > >>> Status: Closed<alexa.ncml>
> > >>
> > >>
> > >
> > >
> > > Ticket Details
> > > ===================
> > > Ticket ID: LPW-471935
> > > Department: Support IDV
> > > Priority: Normal
> > > Status: Closed
> > >
> >
> >
> >
> 


Ticket Details
===================
Ticket ID: LPW-471935
Department: Support IDV
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.