Dear list,
I think I've found a bug with the stackApply() function of the raster package.
The bug was already pointed out at :
http://r-sig-geo.2731867.n2.nabble.com/raster-stackApply-problems-td7589291.html
It says that it was fixed, however I think it wasn't 100% fixed. I've
experienced th
Dear all,
I wrote a code last year that was running well. I've retried the same code
this month and it's not working anymore. The problem arise from using cluster
to do resampling in the raster package on multiple threads. I've tried on two
computers, both have the problem.
Here is a reprod
Dear List,
I've been working on a way to make knn forest maps from satellite imagery and
I'm using both the raster package (to prepare my data) and the yaImpute package
(to do the knn). The problem is that the yaImpute package requires data frames
as inputs and I have rasters. So I have to do:
Dear R Geoer,
This is more a request than a question as I already succeeded at doing what I
wanted to do. However, I'm open to suggestion to do it better, but I really
think is would be a nice feature to add the the as.data.frame() function in the
raster package.
I've been using the as.data.fr
Hello,
I looked at your problem and I can't understand it. What are your trying to
do? It's not clear. Are you trying to find the points that are at less than
200m from ALL other points? Or at 200m of AT LEAST one other point? You have
a distance matrix here, which is n*n, you can difficul
Hello,
I don't have a clear solution for your problem, but I'll try to give you ideas
to where to look that may help you. If I understand well your problem, the
difficulty comes from the fact that you have two POLYGONS and that you are
looking for the COORDINATES.
You could transform your pol
Hello,
I want to expose a problem I am now facing with the gdistance package and the
geoCorrection() function.
I have a code I haven't been using since March, and now, after updating R to
2.15.2 and the package gdistance to 1.1-3 from 1.1-2, the geoCorrection()
function doesn't work. It simpl
So, I've applied Barry's approach to one of my test territory. Barry nicely
qualified is approach as brute-force, so I've made my computer sweat a little.
I've tried 2 iterations per polygon. It was surprisingly not that hard.
First, ~90% of my lakes were remove through simple Pythagorean
Thanks Barry for your interest in my problem. It is indeed an interesting
problem at the same time as a complex one.
I've tried your code and it works for two lakes so far. It's seems like a very
good base for what I want to do. I'll modify it a little to speed it up.
First by removing the
Dear R gurus,
I'm facing a challenge that I have a good feeling you could help me with. So
far I'm stuck right at the beginning so I don't have any example to show you.
Here is what I'm trying to do:
I have a polygon shape of lakes for which I have to be able to automatically
determine if th
Thank you both for your answer.
gridDistance seems to do the trick for me. I haven't seen anything in
gdistance that could help me but I could be wrong.
As for GRASS, I'll have to get into it one day. This thing looks powerful, but
it's pretty much just a name for me so far...
Bastien
Hello R people
I want to create a buffer around shapelines that would go around obstacle like
shown in that figure:
https://www.dropbox.com/s/8qhkj6atkfllzky/unreachable_buffer.jpg
Here is the idea: I have field teams that cannot walk more than 1.5 km away
from a road. I need to know what par
Thanks Roger for your response,
I'm happy that the problem is now known, however I'm afraid I won't be able to
help much with it, I'm no programmer just a user. Hopefully somebody out there
will be able to put your explanations to good use and provide a long term
solution.
Thanks again,
Bast
Dear list,
I have to produce shapefile for a coworker which uses ArcGIS and I've hit a
problem with the writeOGR function from the rgdal package.
Here is an example:
###
> library(rgdal)
Loading required package: sp
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded
Hello Megan,
Personally, I import my .img files with the package Raster.
Try:
Elev <- stack("file_name.img")
Than you can see the result with:
Str(Elev)
And something like:
Plot(Elev)
See: http://cran.r-project.org/web/packages/raster/raster.pdf
For more details
Bastien Ferland-Raymond,
Hello German,
The technique you propose is unorthodox, but it works perfectly! Very fast and
easy, it's exactly what I needed.
Thanks!
Bastien
-Message d'origine-
De : geotux_tux...@linuxmail.org [mailto:geotux_tux...@linuxmail.org]
Envoyé : 18 avril 2012 13:24
À : Ferland-Raymond, B
Dear R people,
I have a code that was using the function dist2Line() from the geosphere
package. The function worked find and did exactly what I was looking for which
is to find the distance between a point (from a SpatialPointDataFrame object)
and a line (from a SpatialLinesDataFrame object)
I Cristina,
I personally had success with the writeOGR of the rgdal package to export shape
to ESRI. I initially had the same error as you, which is not being able to get
the dbf to display the data properly. As Joona said, the problem was related
to the field names. In my case, if I recall
Hello Melanie,
It's really hard to tell what your problem is with no error message or
reproducible example.
However here some info that may help and some trick to help you figure out the
problem
First, gdistance build a transition matrix from a CONDUCTANCE matrix which is
not a COST matrix li
Thanks to Francis and Edzer for their responses.
I been working on my problem for the last 2 days and I managed to get some very
interesting information. I also prepared a reproducible example so people can
try it.
I've found 3 functions that do the thing I want:
1) %over%
2) overlay() (which
Dear geo-list,
I'm just starting using R and the rgdal package to manage and create some
shapes and I am hitting some speed issues while using the %over% function. R is
significantly slower than ArcGIS.
Here is what I'm doing (I've shorten the code to make it easier to follow, I
don't expect i
Hello all,
Thank for the quick answer,
I feel a little bad, the answer was pretty simple, I had to change :
png(filename = "map.png",width=500, height=640 )
with
png(filename = "map.png",width=500, height=640, bg ="transparent")
It's pretty easy and was written in the help file... Even if I
Dear R list,
I have a problem I've been working on for a while now and I'll try to explain
it clearly. It's highly visual and it would be easier to just import images,
however I'm not sure I can do that on the list so I'll try to explain it well.
Here is what I'm trying to do:
1) import a sat
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