About 100 years ago, when I used to program in C++ and use ARCINFO, the ESRI flag value for NODATA in integer grids was -2^31 - 1 (min 4-byte int value - 1).
Michael On 28 April 2010 18:06, Simone Giannecchini <simone.giannecch...@geo-solutions.it> wrote: > On Wed, Apr 28, 2010 at 10:03 AM, andrea antonello > <andrea.antone...@gmail.com> wrote: >> Hi Simone, >> >>> arcgrid reader should use the underlying values for the nodata, it >>> should be -9999 when it is an esri arcgrid, NaN when it is grass. >>> >>> Same should apply to aig, as I told you yesterday I would check the >>> underlying value first. >> >> sure. I was just signaling this to the list, because some could have >> my same problems and not noticing it. >> >> The problem is that: >> - arcgrid not always have -9999.0, > > Indeed, we should the values as advertised in the header, if not let me > know.... > >> as well as grass (grass by default >> uses the *, which isn't even a number and might give the parser >> troubles) > > infact we should advertise Nan > > Simone. > > >> - if you access that all programmatically, you need to know from the >> reader what the novalue it used is. Even if you know what the novalue >> really is. >> >> I'll have to look into this, but not sure I have the time right now. I >> will at least give a quick look and decide what to do with it. >> >> Cheers, >> Andrea >> >> >>> >>> >>> Simone. >>> ------------------------------------------------------- >>> Ing. Simone Giannecchini >>> GeoSolutions S.A.S. >>> Founder - Software Engineer >>> Via Carignoni 51 >>> 55041 Camaiore (LU) >>> Italy >>> >>> phone: +39 0584983027 >>> fax: +39 0584983027 >>> mob: +39 333 8128928 >>> >>> >>> http://www.geo-solutions.it >>> http://geo-solutions.blogspot.com/ >>> http://www.linkedin.com/in/simonegiannecchini >>> http://twitter.com/simogeo >>> >>> ------------------------------------------------------- >>> >>> >>> >>> On Wed, Apr 28, 2010 at 9:54 AM, andrea antonello >>> <andrea.antone...@gmail.com> wrote: >>>> Ok, I will have to look into the code a bit better. >>>> >>>> AigReaders seem to give -Float.MAX_VALUE (probably depending on the >>>> content), while ArcgridReaders -9999.0. >>>> >>>> The gap seems to be in the step between imageio-ext and geotools. >>>> >>>> Will come back when I know something more. >>>> >>>> Cheers, >>>> Andrea >>>> >>>> >>>> On Tue, Apr 27, 2010 at 1:40 PM, andrea antonello >>>> <andrea.antone...@gmail.com> wrote: >>>>> Hi, I am trying to get the value that is used as novalue from a >>>>> gricoverage. >>>>> >>>>> I was assuming something like: >>>>> GridSampleDimension[] sampleDimensions = inCoverage.getSampleDimensions(); >>>>> double[] noDataValues = sampleDimensions[0].getNoDataValues(); >>>>> >>>>> which returned me null. >>>>> >>>>> I then tried to get the categories to manually extract the novalue, >>>>> but these also ended up being null. >>>>> I am using the esri adf (AIGreader) that leverages imegio-ext. >>>>> >>>>> In order to spare time, can anyone tell me if the above is the right >>>>> way to get the value that is used as novalue? >>>>> In which case it is probably a bug and I would open a ticket in the >>>>> imageio-ext world. >>>>> >>>>> Thanks, >>>>> Andrea >>>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> _______________________________________________ >>>> Geotools-devel mailing list >>>> Geotools-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/geotools-devel >>>> >>> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Geotools-devel mailing list >> Geotools-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/geotools-devel >> > > ------------------------------------------------------------------------------ > _______________________________________________ > Geotools-devel mailing list > Geotools-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geotools-devel > ------------------------------------------------------------------------------ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
