[GRASS-user] Re: r.mapcalc

GRASS GRASS user
1

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@tpcsed.com" <ec.jkd@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@tpcsed.com" <ec.jkd@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@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@asu.edu]
Sent: Wednesday, October 17, 2007 7:59 PM
To: ec.jkd@tpcsed.com; atlasis@telecom.ntua.gr; rchirgwin@ozemail.com.au;
silvia.franceschi@ing.unitn.it; josh_0882@yahoo.com; saldinet@yahoo.es;
nkdiitd2002@gmail.com; grassuser@grass.itc.it;
grassuser_request@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@tpcsed.com" <ec.jkd@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