Due to the current gap in continued funding from the U.S. National Science Foundation (NSF), the NSF Unidata Program Center has temporarily paused most operations. See NSF Unidata Pause in Most Operations for details.
Due to the current gap in continued funding from the U.S. National Science Foundation (NSF), the NSF Unidata Program Center has temporarily paused most operations. See NSF Unidata Pause in Most Operations for details.
Hi Ethan, Thanks but there's no public getEnhanceMode() method on VariableDS (http://www.unidata.ucar.edu/software/netcdf-java/v4.1/javadoc/ucar/nc2/ dataset/VariableDS.html). There's a similar method on NetcdfDataset though: http://www.unidata.ucar.edu/software/netcdf-java/v4.1/javadoc/ucar/nc2/d ataset/class-use/NetcdfDataset.Enhance.html. But I can't get a handle to the NetcdfDataset if all I have is a GridDataset (I think). Along similar lines, is there a way to get the underlying file type of a GridDataset/GridDatatype (so I can optimise data-reading algorithms based on what sort of file I'm reading from)? NetcdfDataset.getFileTypeId() works for a NetcdfDataset, but again I can't get this if all I have is a GridDataset. In case you hadn't guessed, this is all part of my effort to refactor ncWMS to be more integrable with TDS. From our previous conversations I believe that TDS will give me GridDataset objects, so that's why I'm trying to work at this level, but if there's a way that the TDS config system could pass me higher-level objects that could work too. Any thoughts? Cheers, Jon -----Original Message----- From: Ethan Davis [mailto:edavis@xxxxxxxxxxxxxxxx] Sent: 11 February 2010 18:34 To: Jonathan Blower Cc: netcdf-java@xxxxxxxxxxxxxxxx Subject: Re: Can I tell if a GridDatatype is "enhanced"? Hi Jon, Not very straight forward and there may be some loopholes I'm missing that John can comment on when he returns. If you call getVariable() on your GridDataype, you will get the backing VariableDS. Call getEnhanceMode() on that and you'll get an EnumSet<NetcdfDataset.Enhance>. If that Set contains Enhance.ScaleMissing, the data you get back will have already had the scale/offset/missing applied. If that set contains Enhance.ScaleMissingDefer, you can directly use VariableDS.convertScaleOffsetMissing() to convert the data. VariableDs also implements VariableEnhance.enhance(Set<Enhance>) but the comments say "DO NOT USE DIRECTLY. public by accident". I'll leave it to John to explain that and comment on the possibility of exposing any of this directly through the GridDatatype. Ethan On 2/8/2010 8:05 AM, Jonathan Blower wrote: > Hi, > > I'm writing a method along the lines of: > > double[] extractDataFrom(GridDatatype grid); > > where the GridDatatype is being passed to me by "foreign" code out of my > control. Do I have any way of telling whether the GridDatatype is > "enhanced", i.e. whether scale/offset/missing attributes are > automatically applied when I extract data? > > And does it matter? Can I program defensively to take care of both > situations (enhanced and not enhanced)? I'm worried that simply > applying convertScaleOffsetMissing() to a value from an enhanced > GridDatatype might actually apply the enhancements twice and hence give > me the wrong answer. > > Thanks, > Jon
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