Statistical computing language and software environment.

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1answer
18 views

Plotting Netcdf data. How to get right projection?

Maybe it's very easy for someone to fix, but I'a a new one in R, so I really need help. I/m trying to plot data containing lat, lon and variable (nmf2). The grid isn't a regular one, so there are some ...
2
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1answer
28 views

Extracting intersection areas in R

I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following: ...
3
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3answers
119 views

Assigning RGB values from Geotiff image to LiDAR data, using R

I have given a Geotiff image and its corresponding Lidar data (x,y,z) in UTM coordinates. I need to merge the Lidar data with the RGB values from the image. That means, at the end, I need to plot ...
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2answers
74 views

Calculate distance between a set of points: lat and long in QGIS or R

I have shapefiles containing the location of several individuals along several months. Positions were documented with a 30 minutes interval. Tables contain the following data fields: collar (ID), ...
0
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1answer
23 views

Sampling one shapefile with polygons of another using R?

I have two shapefiles that partially overlap. One (the bigger one) consists of several polygons which represent fields I am interested in. The second, is a rectangular shape that overlaps about 30% of ...
0
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1answer
31 views

chi-squared for two rasters in R

I am kind of new with statistics. I have two raster with categorical values and I want to get chi-square. How can I do this using R? Rasters have the same region and same resolution. Is chi-square ...
4
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1answer
333 views

R Raster package loop over pixels

I want to perform a trend analysis for each pixel over it's time dimension. Therefore I wrote a loop over each pixel doing the calculation but this is extremely slow. I am sure there must be a faster ...
3
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1answer
35 views

CRS not embedded by maptools in R

I'm using the maptools package in R to merge some data to a shapefile. When I open the original input shapefile in QGIS, QGIS automatically picks up on the CRS. When I open the output shapefile from ...
2
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2answers
57 views

What is the “best” way to automate the GIS slope and aspect algorithm?

I am currently obtaining slope and aspect of roofs using ArcGIS as follows: Mosaic several Lidar .asc files to new raster Extract by mask using Mastermap building outlines to get hold of just the ...
0
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1answer
18 views

ggplot2 plots polygons with wrong topologies

I'm trying to plot polygons in R using ggplot2. In GRASS, QGIS and normal R the map renders fine, but ggplot2 seems to have some kind of topological difficultes I can't explain. With normal R it looks ...
4
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1answer
122 views

Working with MODIS in R

I am new to using MODIS data and was hoping to get some help starting out. I have been able to download the hdf file but viewing it in R has been a problem for me. What I have found so far, and ...
0
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1answer
40 views

Intersection of two Raster objects

I have two raster objects r1 (in grey and green) and r2 (in pink) that I want to intersect with R. I tried with the R function intersect from the raster package but it only intersect the extent of the ...
2
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1answer
81 views

Overlaying lines and aggregating their values for overlapping segments

I have a number of routes (5 in this example data) stored in a SpatialLinesDataFrame called r. These have different origins but all converge on the same destination (Manchester Airport): Each ...
0
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1answer
32 views

How to carry out spatiotemporal analysis? [closed]

I have shapefiles (LULC) of different years. I want to carry out spatiotemporal analysis of the data using r or any other freeware.
5
votes
1answer
205 views

How to build Poisson autoregression model

I have a SpatialPolygonsDataFrame object in R with about 3000 polygons and associated data. I have columns of expected and observed cases. For the moment, I don't have any covariates. I'd like to ...
5
votes
1answer
89 views

Calculating road density in R using kernel density

I have a large (~70MB) shapefile of roads and want to convert this to a raster with road density in each cell. Ideally I'd like to do this in R along with GDAL command line tools if necessary. My ...
3
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4answers
186 views

Convert line shapefile to raster, value=total length of lines within cell

I have a line shapefile representing a road network. I wish to rasterize this data, with the resulting values in the raster showing the total length of the lines that fall within the raster cell. The ...
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2answers
678 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
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1answer
32 views

Conditional statement, apply different equation based on raster value R

I am trying to find the best way to apply a set of equations to a raster conditional on values in a separate raster. For example, suppose r1 has the values of interest and raster 2 (r2) is a raster ...
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0answers
39 views

polygon shapefile R extract issues

I'm trying to do simple RF classification in R based on https://gis.stackexchange.com/a/39103/48810. The code I am using is as follows: require(sp) require(rgdal) require(raster) ...
0
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2answers
24 views

How to compute climatology of 3 days moving averages for rasters pixel by pixel?

I have one year of datasets that I want to compute the climatology of 3-day moving averages and then I subtract this climatology from the original values for each pixel. example: # Set up the ...
1
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1answer
130 views

How to do supervised image classification in saga with the help of R script or Python script

I am using Ubuntu 12.04 and want to do image classification in SAGA. SAGA has numerous classification algorithms which is not present in GRASS and QGIS. I am new to SAGA, but more accustomed to work ...
3
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2answers
79 views

How to load projection along with raster in R?

Why the operation myraster = raster("test.asc") does not load the associated projection file test.prj located in the same directory as test.asc? Does raster() need a specific argument? It seems ...
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0answers
22 views

Optimal distance and power exponent in IDW

I want to apply IDW interpolation for my region of interest, and through leave-one-out cross validation I want to find the optimal values for the distance parameter and the power exponent. I know that ...
0
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1answer
130 views

Spplot labels in R how to change

Can anyone tell me how to change the labels in a legend created by spplot in R? It is a typical vertical ribbon legend automatically generated by spplot. Based on color, it is labelled 1-7 but I ...
2
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2answers
99 views

How calculate pixel by pixel the mode (statistic) of multiple rasters (geotiff)?

I have 12 land cover maps, and I would like to calculate the mode to each pixel of the 12 maps (they have the same resolution and dimension). I mean, the final map would be the mode for each pixel of ...
29
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7answers
10k views

Tutorials to handle spatial data in R?

Does anyone know some good tutorials to handle spatial data in R? I know that there are some packages like rgdal and maptools but I haven't actually found usefull tutorials to get in touch with the ...
1
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0answers
22 views

How to export multiple class training data from ArcGis into R?

I want to perform some machine learning classification of images using R. I'm having issues finding out how to export my training data from ArcGis into R and I'm looking for some help. Currently I do ...
6
votes
1answer
98 views

How to perform a non-linear regression pixel by pixel?

Using nlsLM from Package ‘minpack.lm’ is straightforward for a simple example like this: MODEL:y=(exp(a*x+b*z+c)+d)^f x=c(0.5,0.3,0.2,0.4) z=c(0.1,0.6,1,0.9) y=c(0.2,0.3,0.9,0.9) ...
0
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0answers
23 views

How to avoid a problem of one pixel when doing non-linear regression?

I am ruining a non-linear regression using nlsLM from package:minpack.lm for multiple rasters (pixel by pixel). My initial values may be appropriate for some pixels but not for others.When I run the ...
0
votes
2answers
195 views

projection conversion from mercator to google maps format

Is this spTransform(Finland3, CRS("+proj=longlat +ellps=WGS84 +no_defs+ellps=WGS84 +towgs84=0,0,0 ")) the right way to project a shapefile with this projection coord. ref. : +proj=merc +lon_0=0 ...
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0answers
33 views

Can't import libraries to rsaga

I get this error when I'm trying to import a raster to RSAGA: > rsaga.import.gdal(paste(rast_name, ".tif", sep=""),"RASTER", env= my_env) Module 'GDAL: Import Raster' not found in SAGA library ...
3
votes
2answers
165 views

Spatial Classification

I am not sure what to call my problem. From this image, I have a set of classified polygons (colored). I would like a way to classify the white polygons in the image. I don’t have any attributes to ...
1
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1answer
48 views

Extract area of polygons inside larger polygon and sum their values to a new column

I have two landcover classifications (as shapefiles) created using eCognition. "Level0 (FID)" consist of larger polygons and "Level1 (FID, ClassName, Area_Pxl)" of smaller polygons within these. I ...
1
vote
1answer
124 views

What's the difference in these two shp files?

I'm trying to plot points on these maps in R, with points from "Coordinates" in the same folder. The WL.shp plots fine with the data, but the NG.shp (which should only be larger and of the same area ...
3
votes
2answers
51 views

How to compare a classified raster dataset to another polygon dataset?

I am going to perform an unsupervised classification on my dataset and will get a map as a result. The objective is to rebuild an already existing map (of different soil types) with my new dataset. ...
0
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0answers
33 views

crop shp file leads to different results for same extent

I cropped a shapefile to a smaller extent (my AOI - area of interest) - to work with a reduced working directory. During my workflow I rasterize the shapefile. Here is my problem: I saved both of my ...
0
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1answer
51 views

using raster.predict for Cubist model, factor levels list

I would like to thank in advance any help or advice. Let me know if I need to provide more reproducible data/code. I am working on a Cubist prediction model for soil texture, using continuous and ...
-1
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1answer
55 views

Single point in R

My question might be very simple. I want to create a single point (with xy coordinates) in a specific region, in a specific position. I don't want to do that with qgis I want to do that in R. Is there ...
0
votes
2answers
50 views

Join spatial point data to polygons in R

I am trying to perform a spatial join between point data and polygon data. I have data that indicate the spatial coordinates of an event in my csv file A and have another file, shapefile B, that ...
1
vote
1answer
28 views

Add information from polygon to raster in R

I would like to add information from a spatial polygon to a new raster. r <- raster(nrow=10, ncol=10) r[] <- runif(ncell(r)) * 10 xym = matrix(c(0,0,0,45,45,45,45,0),4,2,byrow=T) ## create ...
2
votes
1answer
92 views

Geographic Heatmaps with Concentric Circles by Distance

I'm looking to generate a geographic heatmap (using 'ggmap') that overlays some dimension (to start, housing prices) over the lat/lon near a city center. Then I want to create circles of equi-distant ...
1
vote
1answer
47 views

unsupervised random forest classification in R

I want to compute an unsupervised random forest classification out of a raster stack in R. The raster stack represents the same extent in different spectral bands and as a result I want to obtain an ...
6
votes
3answers
753 views

Spatio-temporal block kriging with R package gstat?

In the documentation of sp I saw that the coords argument of the SpatialPolygons function only accepts 2 columns. Is it not possible to create 3-dimensional polygons? I am doing spatio-temporal ...
1
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0answers
47 views

Problem between files with same coordinate reference system

I have 2 shape-files. The first created with Qgis and the other with R studio(driver=ESRI). When I import them in qgis i see they doesn't "fit". Both have EPSG:4326 - WGS 84. The only difference I ...
6
votes
2answers
220 views

How to make a bivariate colour ramp with QGIS, R or similar?

Many recent maps I have seen have these neat two-way color gradients that can be used to color correlations between continuous estimates. Here is an example taken from a recent publication (Source: ...
2
votes
1answer
398 views

Mapping Geocoded addresses onto Census shapefiles in R

I have a list of addresses that I have geocoded to get the corresponding longitude and latitude. > AddressDetail <- geocode(match_address) > coordinates(AddressDetail) <- c("lon", "lat") ...
2
votes
1answer
73 views

R function for Thiessen Polygons

For a point data set with temperature data I have, I want to create their Thiessen Polygons in R. So far, the only algorithm I have found is that of Carson Farmer ...
4
votes
3answers
75 views

How can I snap one set of points to another in R

I would like to snap one set of points (SpatialPoints* objects) to another in R using Euclidean distance. I'm hoping for a function like maptools::snapPointsToLines. The attributes of the points ...
6
votes
5answers
4k views

how to overlay a polygon over SpatialPointsDataFrame and preserving the SPDF data?

I have a SpatialPointsDataFrame with some additional data. I would like to extract those points inside a polygon and at the same time, preserve SPDF object and its corresponding data. So far I've ...