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Raster Data

Georeference, analyze and transform gridded data

Raster data, also known as data grids, stores map data as matrices. Regular data grids require a referencing object, vector, or matrix that describes the sampling and location of the data points. Geolocated data grids explicitly identify the latitude and longitude coordinates of all rows and columns.

Functions

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Reference Objects and Latitude-Longitude Grids

georefcellsReference raster cells to geographic coordinates
georefpostingsReference raster postings to geographic coordinates
refmatToGeoRasterReferenceReferencing matrix to geographic raster reference object
refvecToGeoRasterReferenceReferencing vector to geographic raster reference object
geoloc2gridConvert geolocated data array to regular data grid

Analyze and Manipulate Data

georesizeResize geographic raster
geocropCrop geographic raster
geointerpGeographic raster interpolation
containsDetermine if geographic or map raster contains points
geopeaksGenerate synthetic data set on sphere
imbedmEncode data points into regular data grid
filtermFilter latitudes and longitudes based on underlying data grid
findmLatitudes and longitudes of nonzero data grid elements
changemReplace values in array
encodemFill in regular data grid from seed values and locations

Reference Objects

maprefcellsReference raster cells to map coordinates
maprefpostingsReference raster postings to map coordinates
refmatToMapRasterReferenceReferencing matrix to map raster reference object

Analyze and Manipulate Data

mapresizeResize projected raster
mapcropCrop projected map raster
mapinterpMap raster interpolation
containsDetermine if geographic or map raster contains points
mapoutlineCompute outline of georeferenced image or data grid
changemReplace values in array
encodemFill in regular data grid from seed values and locations
georasterref(Not recommended) Create geographic raster reference object
maprasterref(Not recommended) Create map raster reference object
refmatToWorldFileMatrixConvert referencing matrix to world file matrix

Objects

GeographicCellsReferenceReference raster cells to geographic coordinates
GeographicPostingsReferenceReference raster postings to geographic coordinates
MapCellsReference Reference raster cells to map coordinates
MapPostingsReference Reference raster postings to map coordinates

Topics

Introduction to Geodata in Raster Format

Regular Data Grids

  • Construct a Global Data Grid
    This example shows how to store a matrix in a geographic referencing object. Display the matrix on a map, and specify display properties such as the projection, axes labels, and color map.

Geolocated Data Grids

  • Geolocated Data Grids
    A geolocated data grid is defined by three matrices giving latitude and longitude coordinates and indices associated with the mapped region.
  • Geographic Interpretations of Geolocated Grids
    The dimensions of a map matrix and associated latitude and longitude matrices determines the interpretation of the geographic map data.

Applications of Gridded Geodata