[GRASS-user] Re: r.mapcalc

[Michael Barton]

What version of GRASS are you using? Do you use the GUI interface?

You could get additional help if you would copy your responses to the GRASS
user list.

Michael


On 10/21/07 11:30 PM, "ec.jkd at tpcsed.com" <ec.jkd at tpcsed.com> wrote:

> hi,
> for reclass/recode we need to type Title field also for the rule:
> can you tell me how to fill up that:help says
> Map type conversion
> To simply convert a raster between formats (eg. int to float) the user would
> use the first argument. For example
> 10:1500:0.1:15.0
> would convert an old raster with range between 10 and 1500 to a float raster
> with range bewteen 0.1 and 15.0.
> 
> Value replacement
> r.recode can be used to replace existing cell values by others. The formatting
> is as described above. In following example the values 1, 2 and 3 are replaced
> by 1.1, 7.5 resp. 0.4:
> 
>     r.recode in=oldmap out=newmap << EOF
>     1:1:1.1:1.1
>     2:2:7.5:7.5
>     3:3:0.4:0.4
>     EOF
> 
> can you explain me how to go about it like:
> 1. I have a dgn vector map which i have convetred it into raster
> 2. Now for finding line of sight i will take say two points..one with name "a"
> and another name"b" now how will i reclass or recode the values..and what dose
> this value actually mean?
> plz support me > 
> 
> 
> 
> Jainita,
>> 
>> Create a map with the line of sight you want to analyze. Reclassify it
>> (r.reclass or r.recode) to make the cells in the line you want to analyze 1
>> and the rest of the cells 0.
>> 
>> Michael
>> 
>> 
>> On 10/21/07 10:40 PM, "ec.jkd at tpcsed.com" <ec.jkd at tpcsed.com> wrote:
>> 
>>> Hi,
>>> thank you for yr advice butcan you tell me how to prepare this binary file
>>> 
>>> Thanks,
>>> jainita> 
>>> 
>>> 
>>> 
>>> Jainita,
>>>> 
>>>> Use the binary map setting to specify the area you want to do visibility
>>>> analysis for. It should be 1 where you want visibility/los calcuations and
>>>> 0
>>>> where you don't want this calculated.
>>>> 
>>>> Michael
>>>> 
>>>> 
>>>> On 10/17/07 9:30 PM, "jainita" <ec.jkd at tpcsed.com> wrote:
>>>> 
>>>>> Hi,I tried with r.los but it gives visibility all over i.e in 360degree
>>>>> for
>>>>> the distance specified.
>>>>> But I want only between two points in a line i.e not 360 degree so can you
>>>>> help me with it.
>>>>> I would be really oblige if you help me since I am racking my mail a lot
>>>>> on
>>>>> this and still unable to find the solution
>>>>> Thanking you once again
>>>>> 
>>>>> -----Original Message-----
>>>>> From: Michael Barton [mailto:michael.barton at asu.edu]
>>>>> Sent: Wednesday, October 17, 2007 7:59 PM
>>>>> To: ec.jkd at tpcsed.com; atlasis at telecom.ntua.gr; rchirgwin at ozemail.com.au;
>>>>> silvia.franceschi at ing.unitn.it; josh_0882 at yahoo.com; saldinet at yahoo.es;
>>>>> nkdiitd2002 at gmail.com; grassuser at grass.itc.it;
>>>>> grassuser_request at grass.itc.it
>>>>> Subject: Re: r.mapcalc
>>>>> 
>>>>> Use r.los for line of site calculations.
>>>>> 
>>>>> Michael
>>>>> 
>>>>> 
>>>>> On 10/17/07 5:36 AM, "ec.jkd at tpcsed.com" <ec.jkd at tpcsed.com> wrote:
>>>>> 
>>>>>> hi,
>>>>>> i am working on grass and want to know how r.mapcalc can be used for
>>>>>> calculation of pat_map/mask.
>>>>>> syntax says---------------r.mapcalc pat)mkap="if(where_you_want,1, 0)"
>>>>>> for
>>>>>> creating a map which can be used to calcualte line of sight between two
>>>>> points
>>>>>> can anyone elaborate on it with an eg:say i want to know what all is
>>>>>> beign
>>>>>> seen between any two co-ordinate in map.
>>>>>> Please help,i am doing for the first time
>>>>>> 
>>>>>> Thanking You,
>>>>>> Jainita
>>>>> 
>>>>> __________________________________________
>>>>> Michael Barton, Professor of Anthropology
>>>>> Director of Graduate Studies
>>>>> School of Human Evolution & Social Change
>>>>> Center for Social Dynamics & Complexity
>>>>> Arizona State University
>>>>> 
>>>>> phone: 480-965-6213
>>>>> fax: 480-965-7671
>>>>> www: http://www.public.asu.edu/~cmbarton
>>>>> 
>>>>> 
>>>> 
>>>> __________________________________________
>>>> Michael Barton, Professor of Anthropology
>>>> Director of Graduate Studies
>>>> School of Human Evolution & Social Change
>>>> Center for Social Dynamics and Complexity
>>>> Arizona State University
>>>> 
>>>> phone: 480-965-6213
>>>> fax: 480-965-7671
>>>> www: http://www.public.asu.edu/~cmbarton
>>>> 
>>>> 
>> 
>> __________________________________________
>> Michael Barton, Professor of Anthropology
>> Director of Graduate Studies
>> School of Human Evolution & Social Change
>> Center for Social Dynamics & Complexity
>> Arizona State University
>> 
>> phone: 480-965-6213
>> fax: 480-965-7671
>> www: http://www.public.asu.edu/~cmbarton
>> 
>> 
>> 

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton