read readRegion readRegionTo readShape readSize readTo readTo readTypeid reinit updateShape write writeRegion

readRegionTo() void readRegionTo ( FileMemRegions< TRaster::Dim >  regions, TRaster &  raster  ) const Read a region of the data unit into a region of an existing Raster. Template Parameters T The desired raster type M The desired raster dimension, which can be smaller than the data dimension in file N The region dimension, which corresponds to the data dimension in file Parameters region The in-file region regions The in-file and in-memory regions raster The destination raster There are several options to read a region of the data unit: as a new VecRaster object; by filling an existing Raster object; by filling an existing Subraster object. In the last two cases, the in-file and in-memory regions are given as a FileMemRegions object. For example, to read the HDU region from position (50, 80) to position (100, 120) into an existing raster at position (25, 40), do: const FileMemRegions<2> regions({25, 40}, {{50, 80}, {100, 120}}); image.readRegionTo(regions, raster); where image is the ImageRaster and raster is the Raster. In simpler cases, where the in-file or in-memory front position is 0, factories can be used, e.g. to read into position 0 of the raster: image.readRegionTo<2>({{50, 80}, {100, 120}}, raster);