[GRASS-user] Understanding Raster Map Input Files

[Vidura Dantanarayana]

Hi all,

Thank you very much Moritz Lennert for the explanation and apologize for
the mistake I've done. I will try what you suggest by myself.  Hope It's
okay to questioning again if I found a problem again. Have a wonderful day.
Cheers!!!

BR,
Vidura Dantanarayana.

On Sat, Sep 1, 2018 at 2:04 AM Moritz Lennert <mlennert at club.worldonline.be>
wrote:

> Hi Vidura,
>
> First of all, please keep discussions on the list.
>
> On 31/08/18 09:48, Vidura Dantanarayana wrote:
> > Hi Moritz,
> >
> > Really appreciate your help as we are facing this problem for some days
> > now. First I'm a beginner user. Can you explain what are the categories
> > and how those used in GRASS GIS?
>
> GRASS GIS is an extremely wonderful and powerful tool, but it does need
> some initial learning in order to understand how to use it. Just
> answering the questions below will not provide that for you.
>
> I would suggest that you go through some of the basic introductory
> material, just in order to get a feeling for GRASS GIS, before attacking
> your specific problem.
>
> You could have a look at the following resources (at least for their
> introductory parts):
>
> - https://grass.osgeo.org/grass74/manuals/helptext.html
> - https://grass.osgeo.org/grass74/manuals/rasterintro.html
> - https://grass.osgeo.org/grass74/manuals/vectorintro.html
> -
>
> https://grasswiki.osgeo.org/wiki/From_GRASS_GIS_novice_to_power_user_(workshop_at_FOSS4G_Boston_2017)
> -
>
> http://www.training.gismentors.eu/isprs-summer-school-2016/lesson1/grass-gis.html
>
> Or search for "GRASS GIS" in YouTube for some videos.
>
> > Let's say I need to create custom
> > 1hour_moisture (or any other file), so how can I create these files?
>
> How you create these files depends on the data that you have as input.
>
> If you look at the metadata of the file in the demolocation
> (right-click->Metadata or 'r.info 1hour_moisture' you will this
> information at the end:
>
> |   Data Description:
>      |
> |    generated by r.mapcalc
>      |
> |
>      |
> |   Comments:
>      |
> |    if(fuel_class==4,3,if(fuel_class==8,15))
>
>
> This means that the authors had a raster file called 'fuel_class' and
> used the raster calculator (r.mapcalc) to reclass that file attributing
> the value 3 to those pixels who had class=4 in the original map and
> value 15 to pixels with class=8.
>
> I have no idea what this original map contained, so cannot help you
> further (I don't know much about fire spread modeling).
>
> > Can
> > you look at the following problem again?
> >
> >
> > # 1 categories -----------------------------------------------------> (1)
> > Map of Fire Origin of Bass River Fire --------------------> (2)
> >
> > 0.00 0.00 0.00 0.00 ---------------------------------------------> (3)
> > 0:no data ----------------------------------------------------------->
> (4)
> > 1:fire origin --------------------------------------------------------->
> (5)
> >
> > I need to know how to customize the location of origin. I mean, I want
> > to ignite the fire from another place rather the place specified in demo
> > data.
>
> If you have the origin location as coordinates, you can create a vector
> point at the location using v.in.ascii: in the GUI of that module you
> can enter coordinates interactively. Then you convert the map to a
> raster map using v.to.rast.
>
> Moritz
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20180901/d79a2744/attachment.html>