Geographic utilities for manipulating raster graphics using WGS84 datum

Installation

$ npm install wgs84-raster-util

Methods

cellSize(NWRowCornerCoord, SWRowCornerCoord, rasterHeight)

NWRowCornerCoord: object, GeoJSON point for the NW corner of the raster

SWRowCornerCoord: object, GeoJSON point for the SW corner of the raster

rasterHeight: number, raster height in pixels

Returns

number, square size of a cell in meters

rowBounds(NWRowCornerCoord, NERowCornerCoord, cellSize, rowIndex)

NWRowCornerCoord: object, GeoJSON point for the NW corner of the raster

NERowCornerCoord: object, GeoJSON point for the NE corner of the raster

cellSize: number, square size of a cell in meters

rowIndex: number, index of current row starting at 0

Returns

array, coordinates of a bounding polygon for the row

cellBounds(NWRowCornerCoord, SWRowCornerCoord, cellSize, colIndex)

NWRowCornerCoord: object, GeoJSON point for the NW corner of the row

SWRowCornerCoord: object, GeoJSON point for the SW corner of the row

cellSize: number, square size of a cell in meters

colIndex: number, index of current column starting at 0

Returns

array, coordinates of a bounding polygon for the column

pointCell(extent, rasterDimensions, pointCoord)

extent: array, bounding box coordinates in the form: [xLow, yLow, xHigh, yHigh]

rasterDimensions: object

• width: number, discrete units for row size
• height: number, discrete units for column size

pointCoord: object, GeoJSON point

Returns

object, GeoJSON point containing cell coordinates referenced by pointCoord

Running Tests

Install the development dependencies:

$ npm install

Then run the tests:

$ npm test

Code Coverage

Install the development dependencies:

$ npm install

Then run coverage

$ npm run coverage

View coverage reports

$ firefox coverage/lcov-report/index.html

Browser Bundle

$ npm run build