Statistical computing language and software environment.

learn more… | top users | synonyms

0
votes
1answer
38 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 ...
0
votes
2answers
64 views

Error in which.max() : not yet implemented for large objects in R

I am going to create raster by Julian day that observed maximum value of NDVI within a single year. Actually, I want to know which julian day (or raster) has max value in each cells and get result by ...
0
votes
2answers
68 views

How to create raster map by day that observed maximum NDVI from multiple raster data in R?

I have 11 NDVI raster data, representing single summer. I want to create raster by day (Julian day or name of raster) that observed maximum value. In other words, I want to know which day (which ...
2
votes
1answer
119 views

Interpolation with netcdf4 file

I have a netcdf4 data set that contains array and information about latitude and longitude which can be accessed with the following R command: ncvar_get(dataname, 'lon'); ncvar_get(dataname, 'lat'); ...
1
vote
1answer
41 views

Alternatives to bilinear interpolation for raster extraction in R

I have a set of coordinates for which I want to extract temperature values from a raster. I am using the extract function from the raster library in R. Looking at the interpolation methods, there are ...
0
votes
1answer
20 views

Overlaid raster gets shifted around when printing to pdf or when resizing graphics device with mouse

I've spent the past couple of days learning how to use the maps, raster, and rgdal packages to create nice images, but I'm running into trouble when trying to make pdf's for actually presenting. I'm ...
0
votes
2answers
48 views

Is it permissible to redefine raster resolution (not resample!) in order that it be included in a SDM?

I'm fitting a SDM using R. A requirement is that all environmental predictor layers have the same extent, origin and resolution. I have high resolution bathymetry data (25m) that I will resample to ...
3
votes
1answer
91 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
vote
1answer
85 views

Color region polygons according to cluster label

I want to present data on a map of our country. I have used R for showing the clusters on a country! Here the steps I took: setwd('D:/r/cluster2') channel <- odbcConnectExcel('cluster.xls') data ...
2
votes
3answers
103 views

How to analyze and combine overlaping elevation maps into one?

I have 30 overlapping maps that contain tree density heights (measures between 1-100%) of a large area, and I need to get the highest point by pixel and create a new map with all these highest points ...
0
votes
1answer
26 views

Creating a loop for Lines data (spatial data)

I am trying to build a lines shapefile with the contour lines from the 20 meters isobath from along the East African coast. This contour line of 20 meters has different segments and I have this ...
4
votes
2answers
111 views

join grid or polygon layers in R

I have two grids. Cells in each grid have an attribute. Size of grid cells differs between the two grids and the two grids do not overlay each other perfectly. I would like to create a new layer, ...
1
vote
1answer
45 views

Bounding geo points

I am kinda new to geo data processing. For my sample project I am trying to solve next problem. I have array of geo points. If we place it on plot we can visually see that there are areas where ...
1
vote
0answers
41 views

Display followers count on Google maps using R

How can I plot the count of followers, locations wise on google maps - Im using R language my data is as below: for(i in 1:25){print(friends_obj[[i]]$location)} [1] "London & Glasgow/Edinburgh, ...
0
votes
0answers
20 views

Overlay Shapefile and Raster layer in R [duplicate]

I have a raster layer with climate data from the north of Mexico, part of Canada and the US mainland. I am trying to restrict the climate data to only the zone of the US mainland. To do this I thought ...
2
votes
0answers
53 views

Three-dimensional interpolation of temperature profiles using gstat in R?

I'm working on a problem in which I'd like to interpolate a set of oceanographic temperature profiles over a three-dimensional matrix of unsampled x, y, & z locations. The data to interpolate is ...
0
votes
1answer
73 views

Automating Intersect between two polygon layers

I have a spreadsheet that has county-level occurrences of around 1000 species within the US in the column headings (Species State County). Thus, for some counties there may be multiple species. I ...
6
votes
0answers
66 views

Competing approaches to line & polygon simplification

There seems to be a few theoretical options around at the moment for geometric simplification. Douglas–Peucker seems the most established, followed by Visvalingam's approach (used by d3.js). Now ...
0
votes
1answer
58 views

How can I take a large netcdf and convert it to interpolated values in a different set of coordinates?

I've got a large netcdf (a small portion of the data is here) with the data in an even grid associated with an Albers Equal Area Conic projection. I've got the corresponding latitudes and longitudes ...
0
votes
1answer
84 views

Interpreting Moran's I results

I have a sample of data taken from regions of a country! i want to test if there are any spatial autocorrelation on my data using Moran Indice test. the null hypothesis: is that there is no spatial ...
1
vote
1answer
80 views

NDVI time series in R — how do I create a time series object from a data frame?

I am doing a time series analysis of NDVI using the bfast package in R. Bfast requires a time series (TS) object. I have successfully created a data frame with the NDVI at various point locations ...
0
votes
0answers
14 views

Plotting two shapefiles using R? [duplicate]

I'm not familiar with using R for GIS. I was wondering if you can help me figure out how to plot different shapefiles at the same time. I'm using the "map" function to generate a map in order to get ...
2
votes
1answer
32 views

R - Occasional error when using alphahull package areaahull() function

I've recently started using the fantastic alphahull R package, which works beautifully most of the time but occasionally I am getting the following error when running the areaahull() function: Error ...
11
votes
2answers
2k views

How to efficiently read a kml file into R

Hi I'm working with huge .kml files (up to 10 Gb) and need an efficient way to read them into R. Until now I've been converting them to shapefiles via QGIS and then back into R with readShapePoly and ...
4
votes
1answer
77 views

Specifying Bayesian Spatially lagged dependent (SAR) variable regression in winBUGS or Stan

I have been looking for code example on how to specify a SAR spatially lagged dependent variable regression in winBUGS (geoBUGS) or, if possible, in Stan. I mean, something of the format: Y = beta_0 ...
2
votes
1answer
44 views

How to batch generate thumbnails of raster layers with R?

I have been using R to maintain a rather large stack of raster layers (over 700 layers of data for sub-Saharan Africa). Each layer looks as follows ...
10
votes
5answers
4k views

How best to fix a non-noded intersection problem in PostGIS?

I'm using a PL/R function and PostGIS to generate voronoi polygons around a set of points. The function that I am using is defined here. When I use this function on a particular dataset I get the ...
0
votes
1answer
80 views

Conducting geographically weighted regression on a raster

I have a relatively big raster file on which I want to conduct geographically weighted regression. Size of raster ~ 2 GB and number of rows is around 100,000 One way might be to convert from raster ...
0
votes
0answers
19 views

Spatio-temporal Overlay

I have a SpatialPointsDataFrame that lists satellite-detected fires (firesutm), including location and date. I also have a SpatialPolygonsDataFrame with county boundaries (countyutm). I would like ...
2
votes
0answers
64 views

Ecoregions shapefiles: subsetting, extracting and summarizing data from raster

I am attempting to subset and project an ecoregions shapefile from : EPA ECOREGIONS my data set is found here: SHAPEFILES and RASTER When I run this code, two major problems occur: 1) I cannot get the ...
0
votes
1answer
47 views

Want to get an SHP file for my coutry Algeria

H everyone , i'm running a clustering test on my country with R, but the problem the clustering doen't look good because of the map i have, i hant to get a bigger map of my country 'ALGERIA' in an SHP ...
1
vote
1answer
91 views

Creating grid polygons from coordinates using R or Python

I have locational data with north-south and east-west coordinates, with a resolution of 100 meters squares. Each data point's location is somewhere within the 100 meters square which centre is given ...
0
votes
0answers
26 views

R equivalent of GRASS r.grow?

What is a good R equivalent of the GRASS function r.grow? The closest I've been able to find is the script suggested by whuber in response to Creating randomly shaped clumps of cells in a raster from ...
0
votes
0answers
37 views

how to compare multiple time series of raster files

I am looking for the best way to compare the spatial patterns of multiple time series composed of many raster files, in R. The cell values of each raster is continuous, and I am comparing time series ...
0
votes
0answers
28 views

Applying Spatial Clustering test using R? [duplicate]

I’m very new to R so please bear with me: I have a set of area infested by a disease (AIS) annually data and I want to apply some cluster methodology to detect regions with similar (AIS) patterns. I ...
2
votes
0answers
59 views

Performing Moran Test using R?

I’m very new to R so please Bear with me: I have a set of data containing AREA Infested for each region ! and I want to know if there are any spatial autocorrelation between the regions! Here a sample ...
0
votes
0answers
24 views

Performing Mutiple Correspondence Analysis (MCA) using R?

I want to apply MCA (multiple correspondence analysis) to a data table containing regions as individuals, and INFESTED AREA as variable and degree infested also and the type of trees infested , and I ...
0
votes
2answers
269 views

Return column number of min value in dataframe [closed]

So as a result of a bunch of preceding calculations I end up with a dataframe of varying numbers of rows and columns. I want to find the minimum value of the df and return the row and column index. ...
39
votes
10answers
4k views

What is the most useful spatial R trick?

R is becoming pretty strong tool for handling and analyzing spatial data. I learned some useful things through questions like these at SO and thought it might be useful to have something simmilar, but ...
2
votes
0answers
69 views

python equivalent of spatstat's spatial point process functions

Is there a free python package (i.e. PySAL?) that implements the standard summary statistics for spatial point processes, e.g. the F, G, J, and K functions? I'm happy to use R (i.e. spatstat) if ...
14
votes
2answers
2k views

Performing Raster Noise Reduction and Edge Smoothing?

I have a raster image like this I want to delete the isolated noise point and smooth the edge (say the white single points, and I want the edges of the entity look smooth). How can I do this in ...
0
votes
0answers
22 views

glm with raster data: species decline~ ndvitrend

I have species decline data (number of population per year, over a period of 23 years) out of ndvi data for these 23 years I calculated the trend, and mapped it. now i'd like to relate the negative ...
1
vote
1answer
37 views

How to compare multiple spatial point patterns over a polygon

I have multiple point pattern distributions over the same region/polygon. Each point pattern distribution has different number of points. Here is an example of two spatial point patterns for the ...
1
vote
0answers
19 views

Finding the best way to prepare raster image for a function in R

I'd like to ask what is the best way to prepare big raster images in R to run a function on whole images. I have 30 tiff images with the size of ncol=12648, nrow=4144. I read them in R separately. ...
2
votes
1answer
80 views

Running Random Forest Classification on WorldViev-2 image in R - problem

I have a problem with performing RF in R for a WorldView-2 Scene. I've never ever before used R for remote sensing classification, so I simply followed what is written here. I've loaded scene (8-band ...
11
votes
1answer
1k views

How to perform Random Forest land classification?

This is a follow-up to a previous post: Machine Learning Algorithms for Land Classification. It seems that the Random Forest (RF) classification method is gaining much momentum in the remote ...
2
votes
1answer
37 views

changing attributes or names of shapefiles

I am trying to join a subset of two similar shapefiles, one with states from the US and the second with provinces from Canada. The datasets are available here: shapefiles from Geocommons I noticed ...
2
votes
0answers
22 views

In R, set NA cells in one raster where another raster has values

I have two rasters in R. I want to set values to NA in the first raster where the second raster has values. I think this should be simple, using the raster package, with two RasterLayer objects ...
2
votes
0answers
67 views

R - how to create a pre-determined number of identical square polygons to use for a choropleth map?

I am trying to plot crime data density (again!) over a city map, say of NY. As a well known problem there are plenty of examples on this ...
0
votes
0answers
53 views

Test for spatial randomness with Ripley's K or L function in R

I have a spatial point pattern that I would like to test against complete spatial randomness. I managed to plot a Ripley's K function for my data and a function for a random distribution with a ...