Utility Functions

Utility functions for running CODED and dealing with outputs.

To load all the necessary functions for the running CODED, the changeDetection and dataUtils files must be laoded:

var dataUtils = require('users/bullocke/coded:coded/dataUtils')
var codedUtils = require('users/bullocke/coded:coded/changeDetection')

submitCODED

Usage:

submitCODED(saveRegion, params, trainingData)

Description:

Main function for running CODED.

Arguments:

saveRegion (Feature Collection): Geographic region to run the analysis.

params (Dictionary): Dictionary defining CODED parameters.

trainingData (Feature Collection): Feature points containing training data with unique land cover labels identified in the ‘label’ attribute.

Example:

var results = codedUtils.submitCODED(saveRegion, params, trainingData)

makeImage

Usage:

makeImage(arrayImage, column, prefix, startYear, endYear)

Description:

Make a saveable image from the data array output that is retured by CODED.

Arguments:

arrayImage (array): Output array image from CODED

column (int): column of multi-dimensional array image to turn into image.

prefix (string): Prefix to give to all bands in output image

startYear (int): First year in study period.

endYear (int): Last year in study period.

Example:

var disturbances = dataUtils.makeImage(results, 0, 'dist_', params.get('start'), params.get('end'))

reduceBands

Usage:

reduceBands(changeBands, params)

Description:

Reduce the number of output bands to just save information about the number of disturbances specified in the parameter file.

Arguments:

changeBands (image): Images representing CODED output disturbances, magnitude, post-disturbance land cover, and change difference.

parameters (dictionary): CODED parameter dictionary.

Example:

var results = codedUtils.submitCODED(saveRegion, params, trainingData)

var disturbances = dataUtils.makeImage(results, 0, 'dist_', params.get('start'), params.get('end'))
var magnitude = dataUtils.makeImage(results, 1, 'mag_', params.get('start'), params.get('end'))
var postChange = dataUtils.makeImage(results, 2, 'post_', params.get('start'), params.get('end'))
var difference = dataUtils.makeImage(results, 3, 'dif_', params.get('start'), params.get('end'))

var changeBands = disturbances.addBands([magnitude, postChange, difference])
var save_output = ee.Image(dataUtils.reduceBands(changeBands, params))