[Gvsig_english] raster limitations

[Francisco José Peñarrubia]

About [6], you can assign colors to raster. Have you tryed?


El 27/09/2012 11:06, maria maluenda escribió:
> On 26/09/12 16:25, Andre Pais wrote:
>> Hi there. I´ve downloaded the latest gvSIG version, 1.12 final. I´ve
>> installed it (activated GRASS and SAGA in the Sextante options) and used
>> right away because I have an academic work which consists of developing a
>> spacial analysis exercice using raster operations, first using ArcGIS and
>> then I must replicate it using an opensource, in my case gvSIG. In the
>> process, here are a few problems I´ve came up to:
>>
>> 1 - Sextante doesn´t allow to create a DEM-TIN like I did using 3d Analyst
>> of Arcmap; SAGA has a function called "Shape to TIN" but it doesn´t
>> generates an output ;
>>
>> 2 - I need to create a DEM in order to generate slope and aspect charts for
>> my area of study. Since there isn´t an option to define a mask (like there
>> is in Arcmap), I did a clip using the shape with altimetric information as
>> input and the area of study as clipping layer. The result has the altimetric
>> information for my area of study. Then I need to rasterize this result
>> layer. So I went to Sextante and used "Rasterize vector layer" in order to
>> convert it to raster format, having defined an appropriate cell size and the
>> extent as my area of study ( in the hope that the result would have the form
>> of my area of study). Then I did a void filling ( I´ve read this somewhere)
>> to generate a proper DEM. But unfortunately the result is a rectangular DEM
>> instead of being limited to my area of study (which by the way is the
>> portuguese equivalent to an ayuntamiento) Why?
>>
>> 3 - There is an option in Sextante called "Rasterize vector layer (for
>> mask)" but it doesn´t seem to do what i want.
>>
>>
>> 4 - The GRASS function v.to.rast is to confusing and doesn´t work properly.
>> It gives an error :Failed to import data into GRASS mapset;
>>
>> 5 - The reclassify function of sextante is a bit confusing as well. It
>> requires a min value, a max value and a new value. For example, if i need to
>> reclassify a slope chart, e.g, 5 classes (0-10%, 10-20%, 20-30%, 30-40% and
>>> 40%). I have put the min and max for the each class. Why do I need to write
>> new values? Shouldn´t the program assume that? I´ve tried to write 1, 2, 3,
>> 4 ,5 (to match the classes) but the output has 0 value in some pixels but
>> there is no class 0. Why?
>>
>> 6 - Why haven´t the programmers of the latest version improved the symbology
>> options and visualization in rasters. It´s a pain having to work in black,
>> grey and white and not be able to see the classes of a certain raster with
>> different colors (with this being shown in the view)
>>
>>
>> Thank you very much for the attention. I would be really thankful for
>> answers to my questions. It´s kind of an emergency.
>>
>> Regards, André Pais.
>>
>>
>>
>>
>>
>> --
>> View this message in context:http://osgeo-org.1560.n6.nabble.com/raster-limitations-tp5004684.html
>> Sent from the gvSIG users mailing list archive at Nabble.com.
>> _______________________________________________
>> Gvsig_internacional mailing list
>> Gvsig_internacional at listserv.gva.es
>>
>> To see the archives, edit your preferences or unsubscribe from this mailing list, please access this url:
>>
>> http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional
>
> Hi, you could have a look at videos [1] and [2]. They belong to 
> previous versions but could be useful.
>
> [1] http://www.youtube.com/watch?v=T0-_ny4Cj9U
> [2] http://www.youtube.com/watch?v=IY0HlHLadwU
>
> Regards
>
> -- 
> María Maluenda Rico
> Proyecto gvSIG
> Conselleria d'Infraestructures, Territori i Medi Ambient
> València (Spain)
>
>
> _______________________________________________
> Gvsig_internacional mailing list
> Gvsig_internacional at listserv.gva.es
>
> To see the archives, edit your preferences or unsubscribe from this mailing list, please access this url:
>
> http://listserv.gva.es/cgi-bin/mailman/listinfo/gvsig_internacional

-- 
Fran Peñarrubia
Scolab
www.scolab.es

Asociación gvSIG
www.gvsig.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://listserv.gva.es/pipermail/gvsig_internacional/attachments/20120927/3c8a3a33/attachment.htm