NOTE: This library has been replaced by RasterFrames, and is now end-of-life. Please consider switching to this enriched take on supporting geospatial imagery in Spark SQL.

Experimental facility for encoding GeoTrellis types into Spark Datasets/Dataframes.

For usage examples, see the test specification.

To initialize the GeoTrellis support, call the following function in your Spark setup code:

gtRegister(sqlContext)

A smattering of functions currentlly available via Spark Dataframes (prepend st_ for access to SQL variants):

• randomTile(columns, rows, cellType) - Create a tile with random cell values.
• explodeTiles(tileColumn) - Create a row for each pixel in tile.
• explodeTileSample(sampleFraction, tileColumn) - Create a row for each pixel in tile with random sampling.
• tileRows(tileColumn) - Query the number of rows in a tile.
• tileCols(tileColumn) - Query the number of columns in a tile.
• focalSum(tileColumn, radius) - Compute the focal sum of a tile with the given radius.
• localMax(tileColumn) - Compute the cellwise/local max operation between tiles in a column.
• localMin(tileColumn) - Compute the cellwise/local min operation between tiles in a column.
• localAdd(leftTileColumn, rightTileColumn) - Cellwise addition between two tiles.
• localSubtract(leftTileColumn, rightTileColumn) -Cellwise subtraction between two tiles.
• localAlgebra(localTileBinaryOp, leftTileColumn, rightTileColumn) - Perform an arbitrary GeoTrellis LocalTileBinaryOp between two tile columns.
• tileHistogram(tileColumn) - Compute the integral value histogram of cellv values in each tile.tile values.
• tileHistogramDouble(tileColumn) - Compute the floating point histogram of cellv values in each tile.
• tileStatistics(tileColumn) - Compute min, max, mean, stddev, median, mode, etc. of integral cell values.tile values.
• tileStatsDouble(tileColumn) - Compute min, max, mean, stddev, median, mode, etc. of floating point cell values.
• tileMean(tileColumn) - Compute the mean of all integral cell values in each tile.
• tileMeanDouble(tileColumn) - Compute the mean of all floating point cell values in each tile.
• localStats(tileColumn) - Compute cell-local aggregate descriptive statistics for a column of tiles.
• aggHistogram(tileColumn) - Compute the full column aggregate floating point histogram.
• aggStats(tileColumn) - Compute the full column aggregate floating point summary statistics.
• renderAscii(tileColumn) - Render tile as ASCII string for debugging purposes.