similar to: R Output and ArcGIS

Displaying 20 results from an estimated 7000 matches similar to: "R Output and ArcGIS"

2008 Apr 04
2
Reading an ArcGIS raster file
Dear members, How can I read and plot an ArcGIS raster file into R ? The file has extension .aux and contains floating point bathymetry data. The purpose is to create a spatial model in R that uses ArcGIS map data. I have managed to read and plot various shape files into my R project, but I am stuck with this now. I am new to this list and also to R, so any help would be much appreciated. Many
2008 Sep 12
2
Join data by minimum distance
I am wondering if there is a function which will do a join between 2 data.frames by minimum distance, as it is done in ArcGIS for example. For people who are not familiar with ArcGIS here it is an explanation: Suppose you have a data.frame with x, y, coordinates called track, and a second data frame with different x, y coordinates and some other attributes called classif. The track data.frame has
2009 May 01
1
Problems with 'valid columns' when using merge
Dear all, I am trying to use 'merge' within a loop, however, I receive an error relating to the 'by' argument of the command, as follows: > merge_year <- 1986 > > for (i in 1:10) { # Number of file pairs + assign(paste("merged_arunfek_", merge_year, sep=""), merge(x=paste("arunoff_",start_arunoff, sep=""),
2016 Apr 22
2
Unexpected values obtained when reading in data using ncdf and ncdf4
Dear R Users, I am encountering a problem when reading nc files into R using the ncdf and ncdf4 libraries. The nc files are too large to attach an example (but if someone is interested in helping out I could send a file privately via an online drive), but the code is basic: for(i in 1:length(thesenames[,1])){ data <- nc_open(paste(INDIR, thesenames[i,c("wholename")],
2012 Sep 02
1
why variations in accuracy between R to ARCGIS for the same point reprojection?
Hi everyone, I wonder if anyone knows the reason why the outputs of the same reprojection in r and arcgis are different?. The magnitude of the change can be up to 40 km in the poles. Basically, I have a database of points equally separated by one degree over the globe. In ARCGIS, I am projecting the data in GCS-WGS-1984 and then reprojected it to Berhmann to ensure equal area
2009 Aug 17
3
Reshape package: Casting data to form a grid
Dear R Users, I'm trying to use the 'cast' function in the 'reshape' package to convert column-format data to gridded-format data. A sample of my dataset is as follows: head(finalframe) Latitude Longitude Temperature OrigLat p-value Blaney 1 -90 -38.75 NA -87.75 17.10167 NA 2 -90 135.75 NA -87.75 17.10167 NA 3 -90 80.25
2004 Feb 25
2
writing polygons/segments to shapefiles (.shp) or other ArCGIS compatible file
I am not sure a previous e-mail reached the list (no mail aknowledgement from R-boundle etc.). The question was how to write polygon or segment coordinates into a shapefile set or any other ArcGIS supported format. The library shapefiles seems to do something but the documentation is a bit beyond of my mind.... and I cannot get the meaning of the functions write**** and its application to the case
2002 May 24
5
intersecting polygons and conversion from decimal degree to km
Dear all, 1. How can I compute the intersecting area between 2 polygons ? 2. I have polygons with coordinates in decimal degrees (i.e. 13 deg 30 min = 13.5 decimal degrees). I want to compute their area and get the results in square meters or square kiometers. Can anyone give me a conversion coefficient or a pointer where I can find this information (sorry for this off topic question) ? Thanks
2010 Mar 05
1
hier.part
Hi everyone, A beguinner question. - How shall i import 9 different ascii (created from a gis layer (arcmap grid)) into R to create a single dataframe for using in hier.part? Should i use read.table, then turn each created object into a single vector using unlist and finally use data.frame to joint all the vectors into a unique data frame (xcan in the usage of hier.part) ? I´ve been trying to
2006 Mar 24
1
who can tell me the reason why it is different on calculating Moran's I using ARCGIS, Geoda and R?
The attachment is my dataset: 1.ccc.shp (the original data) 2.ccc.gwt, which is computed by Geoda; Introduction to the variables in my data: ID: key variable; N_LATITUDE: latitude measured by GPS; E_LONGITUD: longitude measured by GPS; LIVES: attribute data I get the different result of Moran's between ARCGIS and Geoda, R, why? ARCGIS:spatial statistics tools:spatial
2017 Nov 22
2
How to produce rainfall maps
Fwiw the engine behind geom_raster needs explicit observation-per-row form for input (with no structural normalization), so conversion to points is perfectly proper here, albeit confusing in context. (It's closer to what graphics devices actually use ultimately, but the expansion is laid out very early in ggplot2 because there's no standard for intermediate forms.) Cheers, Mike On Wed,
2008 Sep 05
2
Use of colour in plots
Dear all, I have 3 datasets all of which share the same longitude and latitude values, which I'm looking to plot onto a scattergraph. The third dataset has values which can only be either '1' or '2'. So to incorporate all three datasets onto two axes, I'm wondering if I can plot dataset1 and dataset2 as normal, but then use colour to determine whether these points are
2008 Jul 15
3
Melt (reshape) question
Dear all, I have a grid of 720 columns by 360 rows of global population density values, and hope to convert this to column format using the 'melt' command in the 'reshape' package. I'm not receiving any errors as such, but when the code has finished running, my output looks like this: > head(PopDens.long) Latitude Longitude PopDensity 1 -84.75 V1 0 2
2009 Apr 08
2
Reshape - strange outputs
Dear R Users, I am using the reshape package to reformat gridded data into column format using the code shown below. However, when I display the resulting object, a single column is fomed (instead of three) and all the latitude values (which should be in either column one or two) are collected at the bottom. Also, the NA values aren't removed, despite this being requested in the code. Code:
2009 Jan 12
3
Working with duplicated rows
Dear all, I have a dataframe of 3 columns, consisting of 'longitude', 'latitude' and a corresponding 'value'. Where identical 'longitude' and 'latitude' pairs occur more than once, I want their corresponding 'value' to be summed and the 'pair' to only appear once. For example: long lat value 10 20 5 6 2 3
2016 Apr 22
0
Unexpected values obtained when reading in data using ncdf and ncdf4
On Fri, Apr 22, 2016 at 1:32 AM, Louise Mair <louise.mair at slu.se> wrote: > Dear R Users, > > I am encountering a problem when reading nc files into R using the ncdf > and ncdf4 libraries. The nc files are too large to attach an example (but > if someone is interested in helping out I could send a file privately via > an online drive), but the code is basic: > ?[...]?
2009 Apr 28
1
Finding rows common to two datasets
Dear all, I have 2 data frames, both with 14 columns of data and differing numbers of rows. The first two columns are 'Latitude' and 'Longitude'. I want to find the pairs of Latitude and Longitude coordinates which are common to both datasets, and output a new data frame which is composed of these coincident rows. I tried using the 'unique' command, but had difficulties
2011 Nov 15
2
using tapply() with the quantile function?
Hi: Summary: I am trying to determine the 90th percentile of ambulance response times for groups of data. Background: A fire chief would like to look at emergency response times at the 90th percentile for 1 kilometer grids in Cape Coral, Florida. I have mapped out ambulance response times on a GIS map. Then I superimpose a regularly-spaced grid over the response times and spatially join the
2008 Jun 17
2
Reshape or Stack? (To produce output as columns)
Dear all, I have used 'read.table' to create a data frame of 720 columns and 360 rows (and assigned this to 'Jan'). The row and column names are numeric: > columnnames <- sprintf("%.2f", seq(from = -179.75, to = 179.75, length = 720)). > rnames <- sprintf("%.2f", seq(from = -89.75, to = 89.75, length = 360)) > colnames(Jan) <- columnnames
2017 Nov 17
2
How to produce rainfall maps
Dear R users, I need to produce rainfall maps using R. I know that this is possible, I looked though the web, I found the example below reported (the author is Andrew Tredennick). I would ask you if this is the most performing way to make rainfall maps; if yes would someone be able to give me an example of how file.asc and pointfile.csv should be? If no would somebody please show me another way