Focal raster r. Here we briefly discuss some of these.

Focal raster r. Documentation of the raster R package. It supports multiple focal statistics and allows users to work at multiple spatial scales with ease. NAs are always omitted; thus, this stage effectively acts as an NA filler. The raster::focal() function in R is terribly slow, and for the size of my data it will not work. Following terra's documentation I found the function terra::autocor (). Apr 20, 2020 · I am trying to perform focal statistics on a raster in R using a circular window (defined with focalWeight) and the focal function. The pad argument creates virtual rows/columns of NA values to keep the vector length constant along the edges of the raster. The function that you would apply to the moving window would be sum, and the output of this focal sum would indicate the number of cells of your thresholded raster that have value 1 (this corresponds to the number of cells of r that have value getValuesFocal: Get focal raster cell values Description This function returns a matrix (or matrices) for all focal values of a number of rows of a Raster* object Usage # S4 method for Raster getValuesFocal(x, row, nrows, ngb, names=FALSE, padValue=NA, array=FALSE, ) Value If x has a single layer, a matrix with one row for each focal cell, and one column for each neighbourhood cell around Mar 31, 2016 · I am trying to use R with the focal function from the raster package to smooth raster images. #' #' @param x A `GRaster`. They also must be created in a programmatic manner - either from Python, R, or Bash/Command Line. SpatVector supports all types of geometric operations such as intersections. The focal cell is then taken as the mean, sum, minimum or maximum of the weighted values (as specified focalWeight: Focal weights matrix Description Calculate focal ("moving window") weight matrix for use in the focal function. rm = TRUE) ) As a gut check, we can also write our own ratio function and pass it to focal. Apr 27, 2021 · The problem came down to not enough horsepower for the processing. getW . I am new to R. Can be used to determine the cells of x for which focal values should be computed. ratio <- function(x, value = 1) { Apr 4, 2025 · Local correlation coefficient for two RasterLayer objects (using a focal neighborhood) or for two RasterStack or Brick objects (with the same number of layers (> 2)) In most cases, the result of a focal analysis is a smoothed version of the input raster, where variation at smaller scales than the summary window is removed and broader scale spatial patterns are emphasized. Calculate focal ("moving window") values for the neighborhood of focal cells using a matrix of weights, perhaps in combination with a function. #' #' @param w Numeric integer or a square matrix with an odd My approach firstly converted my rasters: class and ref using focal approach, majority filter to foc. Is this cor Jul 10, 2018 · I am running a Focal function in R calculating the mode within my moving window. A weights matrix of numeric values can also 8. 8-60) Spatial Data Analysis Description Methods for spatial data analysis with vector (points, lines, polygons) and raster (grid) data. The function used should return a single value, and the number of layers in the output Raster* equals the number of unique values in indices. Input and output are rasters of class stars, single-band (i. Overview Calculates statistics on the cells within a neighborhood around each cell of an input raster. Many spatial operations have a non-spatial (attribute) equivalent, so concepts such as subsetting and joining May 31, 2019 · Moving window analysis, sometimes referred to as focal analysis, is the process of calculating a value for a specific neighborhood of cells in a given raster. Usage ## S4 method for signature 'SpatRaster' Jan 5, 2021 · Calculate focal ("moving window") values for the neighborhood of focal cells using a matrix of weights, perhaps in combination with a function. circular) windows. Calculate focal ("moving window") weight matrix for use in the focal function. This will return a RasterBrick with two layers. Methods for vector data include geometric operations such as intersect and buffer. 1. However, when I do, for instance, the following, the calculation &quot;. However, after running focal (m, w=19, fun=mean, na. Currently, only the landscape level metrics are possible to calculate and they can be specified similarly to calculate_lsm(). I am Aug 10, 2018 · The raster values associated with the zero values in the focal matrix are not passed to the function called within raster::focal. 5 meter resolution raster (NDVI) over 55,000 sq miles (half of Colorado) against 50,000+ points with a lot of overlap just killed the server. However, the function to apply to the window needs to be caclulated relative to the center cell of said window. The predict and interpolate methods facilitate the use of regression type (interpolation, machine learning) models for spatial prediction, including with satellite remote sensing data. frame (r, xy=TRUE) colnames (r_df) <- Available with Image Analyst license. Spatial Joins: Can be done in multiple ways (e. I used the idw function from the gs 4. This problem does not occur when I simply read in the raster using rast () and then write it using writeRaster (), but it happens when I use focal 5. Instead of using the default buffering mean function, I need to use vector averaging since my wind direction is in Dec 21, 2021 · I want to perform a neighborhood analysis in R to smooth the layer I have but keeping all the NAs of the input raster intact. Sep 30, 2020 · 1 I'm using the function focal_hpc from spatial. Many spatial operations have a non-spatial (attribute) equivalent, so concepts such as subsetting and joining High-level methods Several ‘high level’ methods (functions) have been implemented for SpatRaster objects. See focal for two-dimensional focal computation. Unfortunetly, the modal option is not providing the expected result. Available with Spatial Analyst license. Explore its functions such as addLayer, adjacent or aggregate, its dependencies, the version history, and view usage examples. I found an article online describing the method using RStudio. Visually, the results look similar but the Feb 8, 2020 · I'm trying to normalize a DEM raster with focal and a function to set values between 0 and 1 (iteratingly from the neighboring cells). High-level methods Several ‘high level’ methods (functions) have been implemented for SpatRaster objects. Aug 13, 2025 · The most prominent example of a raster calculation based on neighboring cells is moving window calculations, also known as focal filters. It returns a raster that is 99% NA and the remainder are the values at the sample sites. A raster is a spatial (geographic) data structure that divides a region into rectangles called “cells” (or “pixels”) that can store one or more values for each of these cells. , intersect, within distance), unlike non Feb 16, 2016 · Pass the fill. Usage focalWeight(x, d, type=c('circle', 'Gauss', 'rectangle'), fillNA=FALSE) Arguments Focal regression Description Calculate values for a moving-window by comparing the value in one layers with the values in one to many other layers. github. Using the focal() function in the terra package seems to be my best However, a second raster, usually a categorical raster, defines the zonal filters (or ‘zones’) in the case of zonal operations as opposed to a predefined neighborhood window in the case of focal operations (see previous Section). Details This applies a Gaussian Kernel smoother. Apr 4, 2025 · Details The package implements classes for Raster data (see Raster-class) and supports Creation of Raster* objects from scratch or from file Handling extremely large raster files Raster algebra and overlay functions Distance, neighborhood (focal) and patch functions Polygon, line and point to raster conversion Model predictions Summarizing Common raster analyses, available in GIS software, are focal (moving window) functions where a statistic is calculated for a focal cell within a specified window. I expect the edges of both rows/columns to return as NA, instead the output returned is 9,9,9. Jan 13, 2023 · Finding out how many times you need to run focal might be hard. policy="all", fillvalue=NA, pad=FALSE, padvalue=fillvalue, expand=FALSE, silent=TRUE, filename="", overwrite=FALSE Calculate focal ("moving window") values for the neighborhood of focal cells using a matrix of weights, perhaps in combination with a function. You can also change these Aug 27, 2023 · I have a raster which I applied a Gaussian filter. May 29, 2024 · Apply a focal filter on a raster Description Applies a focal filter with weighted neighborhood w on a raster. 2 Map algebra Map algebra is used for a various task related to spatial raster data processing and analysis. The convolution option performs a Gaussian decomposition whereas the other options use the kernel as weights for the given statistic. seed (100) n Sep 15, 2025 · Calculate focal ("moving window") values for each cell of a raster Description Calculate focal ("moving window") values for each cell of a raster using various functions. The high-level methods have some arguments in common. This chapter shows how spatial objects can be modified in a multitude of ways based on their location and shape. More specifically, the raster. Nov 24, 2022 · I have two raster data land cover and carbon monoxide, and I wish to perform correlation analysis on the two datasets. smooth from the spatialEco package and the focal from the terra package. The focal function in the raster package just provides mean, min and max. The first argument is typically Apr 4, 2025 · Get focal raster cell values Description This function returns a matrix (or matrices) for all focal values of a number of rows of a Raster* object Usage ## S4 method for signature 'Raster' getValuesFocal(x, row, nrows, ngb, names=FALSE, padValue=NA, array=FALSE, ) Arguments Mar 20, 2024 · I have issues understanding the operating of the terra::focal function. See the help files for more detailed descriptions. Implementation in landscapemetrics We provide the function window_lsm() in landscapemetrics to analyse an input raster using the moving window approach. When I compare the map before focal and after, it seems that focal with modal is just filling all the wholes with the same value even in spots were there is no way that is true. g. The function allows to specify the neighborhood using a matrix using the terra::focal() function internally. The first argument is Jul 20, 2023 · I have a SpatRaster with multiple layers and I want to calculate the Local Moran's I using R's terra package for each layer. The reason is that I want to try bilinear interpolation, and I don't think a moving window average always gives the same answer as bilinear interpolation. Applies a focal filter with weighted neighborhood w on a raster. focal2r: Apply a focal filter on a raster (R) Description Applies a focal filter with neighborhood size k * k on a raster (class stars), using R code. These are the values of a cell and a rectangular window around it. I would like to move this to an open source alternative but am having trouble finding an open source equivalent to ArcGIS's "Focal Statistics". 1 Introduction Spatial operations, including spatial joins between vector datasets and local and focal operations on raster datasets, are a vital part of geocomputation. In my specific case, I want each cell to be the mean of all cell Applies a focal filter with neighborhood size k*k on a raster (class stars), using R code. Oct 20, 2021 · I am trying to calculate the square of the difference between a raster cell i and its neighbors js (i. Focal operations can be performed using the focal function. 4. You could also write a function that applies the Gaussian weights to the pixels being aggregated but, it would have to match the number of Sep 15, 2025 · Calculate focal ("moving window") values for each cell of a raster Description Calculate focal ("moving window") values for each cell of a raster using various functions. Notes If the input raster is of floating-point type, only the Mean, Maximum, Median, Minimum, Percentile, Range, Standard Deviation, and Sum statistics are available terra (version 1. The default settings will create a global raster data structure with a longitude/latitude coordinate reference system and 1 by 1 degree cells. I have a raster with 3 values (1, 2 and 3) and I would Jan 2, 2017 · I am using the focal function from raster package v2. It can be divided into four groups of operations: Local - per-cell operations Focal - most often the output cell value is the result of a 3 x 3 input cell block Zonal - to summarize raster values for some zones (usually irregular areas) Global - to summarize raster values for one or High-level methods ¶ Several ‘high level’ methods (functions) have been implemented for RasterLayer objects. The solution I finally ended up with was Creation of Raster* objects from scratch or from file Handling extremely large raster files Raster algebra and overlay functions Distance, neighborhood (focal) and patch functions Polygon, line and point to raster conversion Model predictions Summarizing raster values Easy access to raster cell-values Plotting (making maps) Manipulation of raster extent, resolution and origin Computation of Value A new RasterLayer object (in the R environment), and in some cases the side effect of a new file on disk. For example, if you have a RasterStack with 6 layers, you can use indices=c(1,1,1,2,2,2) and fun=sum. Jan 20, 2017 · I was wondering if any of you could help me with the following task dealing with the focal () function in the R raster package. SpatVectorsupports all types of geometric operations such as intersections. If you need even sides, you can use a matrix and add a column or row of NA 's to mask out values. R/focal. Must be one of "all" (compute for all cells), "only" (only for cells that are NA) or "omit" (skip cells that are NA). For each pixel, I want to calculate the percentage of 1s within a 500m radius. SpatRaster supports handling large raster files that cannot be loaded into memory; local, focal, zonal, and global raster operations; polygon, line and point to raster conversion; integration with modeling methods to make spatial predictions; and more. policy="only", na. Contribute to adamlilith/fasterRaster development by creating an account on GitHub. I made a couple of scenarios to better understand how to combine weight matrices and functions to summarize values. By &quot;default&quot;, the Gaussian filter, takes the mean within the kernel. r defines the following functions:#' Calculate cell values based on values of nearby cells #' #' @description This function calculates statistics on a moving "neighborhood" of cells of a raster. Relation to Non-Spatial Operations: Many spatial operations (e. NA values in w can be useful for creating non-rectangular (e. The use of the package is illustrated in subsequent sections. na function to raster::focal and check results. The quick and dirty way is to use focal in the raster package with fun=mean, NAonly=T, na. In fact, the results are identical when padding is used in the focal call. The function performed on the input is a statistic, such as the maximum, average, or sum of all values encountered 4. Usage ## S4 method for signature 'SpatRaster' focalReg(x, w=3, fun="ols", , fillvalue=NA, filename="", overwrite=FALSE, wopt=list()) Arguments Focal operations Focal, or neighborhood, operations produce an output raster dataset in which the output value at each cell location is a function of the input value at a cell location and the values of the cells in a specified neighborhood around that location. Nov 21, 2014 · One to achieve your aim is to perform a focal sum on a binary raster that has been thresholded at 200. The first argument is typically Apr 8, 2022 · I am using the focal function in the terra package to fill holes in a DEM raster. The predict and interpolate methods facilitate the use of regression type Creation of Raster* objects from scratch or from file Handling extremely large raster files Raster algebra and overlay functions Distance, neighborhood (focal) and patch functions Polygon, line and point to raster conversion Model predictions Summarizing raster values Easy access to raster cell-values Plotting (making maps) Manipulation of raster extent, resolution and origin Computation of You can do this in R with a custom function passed to the raster::focal function. R raster package https://rspatial. The focal cell is then taken as the mean, sum, minimum or maximum of the weighted values (as specified with fun). Processing of very large files is supported. class : RasterLayer dimens Focal weights matrix Description Calculate focal ("moving window") weight matrix for use in the focal function. Such continuous spatial data are also referred to as 'grid' data, and be contrasted with discrete (object based) spatial data (points, lines, polygons). Nov 28, 2018 · I have a raster of 1 km wind direction data that I need to run a focal buffer on. Apr 4, 2025 · focal uses a matrix of weights for the neighborhood of the focal cells. I am working with Radar images that have already been preprocessed. I want to fill it by Inverse Distance Weighting (IDW), by considering the 9 nearest [valid] cells. 1 Introduction to Spatial Operations Spatial Operations: Include spatial joins for vectors and local/focal operations for rasters, allowing modification based on location and shape. Aug 7, 2022 · I have a big raster with some NA cells that need to be filled. This package has been superseded by the "terra" package . Explain what interpolation is and the different techniques we can use. ref and after I applied Kappa stat on these rasters. Jul 9, 2014 · I´m trying to calculate moving majority values over an raster in R. e. Raster data manipulation Introduction In this chapter general aspects of the design of the terra package are discussed, notably the structure of the main classes, and what they represent. Utilise vector Faster raster processing in R using GRASS GIS. This function is relatively slow, provided here mainly for testing purposes or for custom using functions which are not provided by focal2. focal uses a matrix of weights for the neighborhood of the focal cells. Sep 30, 2021 · Hi, I have found that running focal statistics with a user defined function with large rasters is slow and sometimes breaks the R session. However, it would be more efficient if you could impute N/As until there are none left within the shapefill. The raster package has been a central tool for working with geospatial data in R. It is computationally much more efficient to adjust the weights-matrix than to use another function through the fun argument. Essentially I'd like to remove some speckle (false positives) from an image (pixels May 17, 2018 · I have raster and lat/long values, I want to perform focal operation on these points using 3x3 window/kernel. Create a buffer around vector geometries or raster patches c(<SpatRaster>) c(<SpatRasterDataset>) c(<SpatRasterCollection>) c(<SpatVector>) c(<SpatVectorCollection>) Jun 23, 2022 · And I get an error " [focal] test failed" when using focal (). This function returns a matrix (or matrices) for all focal values of a number of rows of a Raster* object Mar 20, 2024 · I have issues understanding the operating of the terra::focal function. Available with Image Analyst license. rm=FALSE, pad=FALSE, padValue=NA, NAonly=FALSE, ) Arguments Get focal raster cell values Description This function returns a matrix (or matrices) for all focal values of a number of rows of a Raster* object Usage ## S4 method for signature 'Raster' getValuesFocal(x, row, nrows, ngb, names=FALSE, padValue=NA, array=FALSE, ) Arguments Oct 18, 2022 · I'm not sure why the focal function I've been using in Raster does not work with Terra. terra has a large number of functions, not all of them are discussed here, and those that are discussed are mentioned only briefly. Implement different geostatistical techniques in R. For example, filter=matrix(1/9, nrow=3, ncol=3) would be equivalent to mean with ngb=3 in the focal function. Nov 11, 2022 · The focalMat is creating a Gaussian Kernel (matrix), not a function (eg. Usage ## S4 method for signature 'SpatRaster' focal3D(x, w=3, fun=mean, , na. This is being run on a large raster with a cell size of 56m (see details below). ,(j-i)^2) in a 3 x 3 neighborhood, and then calculate the mean value of those differences and Creating Raster* objects ¶ A RasterLayer can easily be created from scratch using the function raster. Oct 19, 2017 · Own function for focal statistics (focal, "raster" package, R) gives incorrect output Asked 7 years, 3 months ago Modified 7 years, 3 months ago Viewed 972 times Transforming raster data Vector data manipulation Basics Geometry and attributes Variables Merge Records Append and aggregate Append Aggregate Overlay Erase Intersect Union Cover Difference Spatial queries Raster data manipulation Introduction Creating SpatRaster objects Raster algebra ‘High-level’ functions Modifying a SpatRaster object Overview of the functions in the raster package The raster package provides classes and functions to manipulate geographic (spatial) data in ’raster’ format. Usage focalMat(x, d, type=c('circle', 'Gauss', 'rectangle'), fillNA=FALSE) Arguments Apr 12, 2025 · Get focal values Description Get a matrix in which each row had the focal values of a cell. That requires determining the contour of your shapefill and counting N/As only within. data. Usage ## S4 method for signature 'SpatRaster' focalValues(x, w=3, row=1, nrows=nrow(x), fill=NA) Arguments May 27, 2024 · I'm trying to calculate focal statistics on a raster in R using the terra package. In writing a function just keep in mind that each focal window represents a vector (string of values) and is, in effect, a linearized matrix. fastfocal: Fast Multi-scale Raster Extraction and Moving Window Analysis with Fast Fourier Transform (FFT) in R fastfocal provides high-performance, flexible raster smoothing and extraction functions in R using moving windows, buffer-based zones, and an auto-switching FFT backend for large kernels. We would like to show you a description here but the site won’t allow us. frame (r, xy=TRUE) colnames (r_df) <- Three-dimensional focal values Description Calculate focal ("moving window") values for the three-dimensional neighborhood (window) of focal cells. policy="all", fillvalue=NA, pad=FALSE, padvalue=fillvalue, expand=FALSE, silent=TRUE, filename="", overwrite=FALSE Raster methods include local, focal, global, zonal and geometric operations. A function is applied to the first and second layer, then to the second and third layer, etc. library (raster) r <- raster (ncol=10, nrow=10) r [] <- 1:100 f<-function (x,center) {sum (x)*center I am trying to understand circular focal means using rasters having NA values. Usage focalWeight(x, d, type=c('circle', 'Gauss', 'rectangle'), fillNA=FALSE) Value matrix that can be used in focal Focal values Description Calculate focal ("moving window") values for the neighborhood of focal cells using a matrix of weights, perhaps in combination with a function. This would be similar to the focal statistics tool in ArcGIS using the majority raster (version 3. May 18, 2014 · I want to run focal values for neighbourhood of focal cells using a matrix, with a function preferably. I currently avoid the issue by increasing raster cell size fastfocal: Fast Multi-scale Raster Extraction and Moving Window Analysis with Fast Fourier Transform (FFT) in R fastfocal provides high-performance, flexible raster smoothing and extraction functions in R using moving windows, buffer-based zones, and an auto-switching FFT backend for large kernels. SpatRastersupports handling large raster files that cannot be loaded into memory; local, focal, zonal, and global raster operations; polygon, line and point to raster conversion; integration with modeling methods to make spatial predictions; and more. Raster methods include local, focal, global, zonal and geometric operations. I think that you want to apply your kernel function to focal and then aggregate the results to something approximating your kernel size. Details focalFilter uses a matrix of weights for the neigbhorhood of the focal cells, together with a function (normally sum). Apr 12, 2025 · Focal regression Description Calculate values for a moving-window by comparing the value in one layers with the values in one to many other layers. The neighborhood can be a square, circle, or a user-defined set of cells (with or without weights). Apr 12, 2025 · Details focal The window used must have odd dimensions. Oct 19, 2017 · Own function for focal statistics (focal, "raster" package, R) gives incorrect output Asked 7 years, 3 months ago Modified 7 years, 3 months ago Viewed 972 times Calculate values for a moving-window by comparing the value in one layers with the values in one to many other layers. Overview of the functions in the raster package The raster package provides classes and functions to manipulate geographic (spatial) data in ’raster’ format. Raster data divides space into cells (rectangles; pixels) of equal size (in units of the coordinate reference system). Thus, for each cell, a 3x3 matrix is to be created and the fun Focal operations and functions Operations or functions applied focally to rasters involve user defined neighboring cells. After doing this, I turn the original and Jun 6, 2014 · I'm looking for a moving window process for R (like 'focal' in the raster package). Usage focal2(r, fun, ) Arguments Feb 7, 2019 · I'm trying to calculate the majority value in a categorical raster data set in R, for example using land cover data. I tried the divide and conquer through zonal statistics but too many extremely small slivers in the buffered points. ‘High level’ refers to methods that you would normally find in a GIS program that supports raster data. The raster package can be slow and can result in memory issues if large raster data sets are used. tools in R to compute for each cell of a raster the average value (mean function) around windows of a specific size (3 cells x 3 cells). wwarn . I want a 3x3 moving window and I want to calculate the max raster cell. However I can successfully extract values using focalValues () and subsequent apply () seemed does what I need. 5-8 to get max value in a 3x3 window. Raster data divides space into cells (rectangles; pixels) of equal size (in units of the coor-dinate reference system). rm=T and an appropriately sized matrix of 1's as the weights. You can change these settings by providing additional arguments such as xmn, nrow, ncol, and/or crs, to the function. Here we briefly discuss some of these. A typical case is the computation of the coefficients for a focal linear regression model. To carry out a focal analysis, a weights object must be defined using the focalWeight() function. fw[fw > 0] <- 1 fw ( rmean <- focal(r, w = fw ,fun = mean, pad=TRUE, padValue = 0, na. However, recently the originators of raster have released the terra package, which has been designed to replace raster. 6-32) Geographic Data Analysis and Modeling Description Reading, writing, manipulating, analyzing and modeling of spatial data. Usage focal2r(x, w, fun, mask = FALSE, ) Value The filtered stars raster May 29, 2024 · Applies a focal filter with neighborhood size k * k on a raster (class stars), using R code. At the moment, your while loop continues to impute N/As until the whole raster is filled. Apr 12, 2025 · Three-dimensional focal values Description Calculate focal ("moving window") values for the three-dimensional neighborhood (window) of focal cells. The sum of the values adds up to one. Apr 12, 2025 · Focal weights matrix Description Make a focal ("moving window") weight matrix for use in the focal function. rm=TRUE) my DEM is moved ~11cm relative to it's original position (see images below). Trying to process a 0. gaussian. With the help of a similar post and the raster reference manual, my code Nov 12, 2022 · I am comparing smoothing algorithms in R. Window values are typically 1 or NA to indicate whether a value is used or ignored in computations, respectively. terra works to alleviate some of these issues. focal2: Apply a 3x3 focal filter on a raster Description Applies a 3x3 focal filter on a raster (class stars). This simplified example uses a custom function to apply the focal filter only to pixels with a value of 0 an Get a matrix in which each row had the focal values of a cell. R defines the following functions: . Calculate focal ("moving window") values for each cell of a raster using various functions. Utilise map algebra to analyse two or more raster datasets together. Usage ## S4 method for signature 'RasterLayer' focal(x, w, fun, filename='', na. The weights (w) can be added to, subtracted from, multiplied by or divided with the raster values (as specified with weight_fun). html - rspatial/raster I have used the MASK () function in the Raster package of R to extract the the DEM values where they intersect non-Null values of the sample-site raster. As part of that, some calculations Sep 3, 2016 · I am trying to run a multivariate regression with different layers in a RasterStack using focal {raster} or localFun {raster}. I created the following raster: r<-rast (ncol=5,nrow=5,vals=1:25) r_df <- as. How can I take the max, instead of the mean, within the kernel? Her Aug 13, 2023 · I have a raster with coded values of either 0 or 1. The edges are handled by adjusting the window. Calculate values such as a correlation coefficient for focal regions in two neighboring layers. Usage focalWeight(x, d, type=c('circle', 'Gauss', 'rectangle'), fillNA=FALSE) Arguments R/focal. The window is always circular. Oct 1, 2015 · Example with a 3*3 neighborhood where the sum is multiplied with the center value "center". You can do this in R with a custom function passed to the raster::focal function. Utilise vector and raster data together using zonal statistics. The raster package ¶ This vignette describes the R package raster. neighbors: Makes each cell category value a function of the category values assigned to the cells around it, and stores new cell values in an output raster map layer. For Jan 10, 2017 · I'd like to filter a large raster, but only run the filter if the center cell of the window is a specific value. library (raster) library (rasterKernelEstimates) set. Typical functions calculated across the neighborhood are sum, mean, min, max, range, etc. Several shapes of neighborhood are available. , only `"x"` and `"y fastfocal: Fast Multi-scale Raster Extraction and Moving Window Analysis with Fast Fourier Transform (FFT) in R fastfocal provides high-performance, flexible raster smoothing and extraction functions in R using moving windows, buffer-based zones, and an auto-switching FFT backend for large kernels. class and foc. Jun 17, 2018 · There was a great question from @Robert Hijmans about why not use a moving window average with the focal () command in the raster package. The default function is sum. I used to perform this analysis using the similar function focal, which is however slower than focal_hpc when using large raster files. , subsetting, joining) have non-spatial counterparts. For example, to smooth out the elevation raster by computing the mean cell values over a 11 by 11 cells window, type: Apr 4, 2025 · Focal weights matrix Description Calculate focal ("moving window") weight matrix for use in the focal function. My data has 0, 1, and 2 as values, and I want to add values of "1" only, if I am using the focal function. io/raster/reference/raster-package. Apr 6, 2018 · The ideal but computationally heavy way is to convert the raster to SpatialPixels and then use idw () or krige () in gstats package for interpolation, and convert back to raster. Apr 5, 2023 · Thanks so much for the help Robert. 1 Focal Statistics From the docs (Esri 2020): Focal statistics performs a neighbourhood operation that computes an output raster, where the value for each output cell is a function of the values of all the input cells that are in a specified neighborhood around that location. By default, the focal () function will run through each cell of a given raster ('background' raster hereafter) and apply a given function to the neighboring values as defined by a user-defined moving window. checkngb Learning Objectives By the end of this week, you should be able to: Use, analyse and visualise raster data in R confidently. , mean) which is what aggregate is expecting. Notes If the input raster is of floating-point type, only the Mean, Maximum, Median, Minimum, Percentile, Range, Standard Deviation, and Sum statistics are available r. I have followed Applies a focal filter with weighted neighborhood w on a raster. See the help Description The raster package provides classes and functions to manipulate geographic (spatial) data in 'raster' format. With a moving window calculation, raster values are transformed based on the values from a neighborhood surrounding each pixel. glo gsa zjzcm tvze tczgi kyhw icoy mhx sgsfj qzepke