kongdd_packages

Copyright (c) 2019 Dongdong Kong, China University of Geosciences

Keep in mind that this repository is released under a GPL3 license, which permits commercial use but requires that the source code (of derivatives) is always open even if hosted as a web service.

Table of Content

[TOC]

Installation

This repository is a GEE package in JavaScript. You can access it by https://code.earthengine.google.com/?accept_repo=users/kongdd/public.

Functions

1. Visualization

// Load package
var pkg_vis  = require('users/kongdd/public:pkg_vis.js');

• gradient legend, pkg_vis.grad_legend(viz, title, IsPlot, position)

  • viz Visualization parameters.
  • position String, legend position, e.g. "bottom-left", "bottom-right".
  • palette Corresponding colors.

• discrete legend, pkg_vis.discrete_legend(names, palette, title, IsPlot, position)

  Legend examples: https://code.earthengine.google.com/c35e156e943370c1dd363732a5b59531.

• Layout layout works like layout in R and subplot in MATLAB , which is used to produce multiple maps.

2. Temporal interpolation

// load package
var pkg_smooth = require('users/kongdd/public:Math/pkg_smooth.js');

• Linear interpolation, pkg_smooth.linearInterp(imgcol, frame, nodata)

  Example: https://code.earthengine.google.com/3b08f56a5f646104c742be584877e94e.

• Historical average interpolation: pkg_smooth.historyInterp(imgcol, imgcol_his_mean, prop, nodata)

  Example: https://code.earthengine.google.com/3b08f56a5f646104c742be584877e94e.

• wBisquare_array Bisquare weights updating function

3. Trend Analysis

// Load package
var pkg_trend = require('users/kongdd/public:Math/pkg_trend.js');

• aggregate_prop: works like aggregate function in R .

  // add the property of Year, YearStr, YearMonth, Season
  imgcol      = pkg_trend.imgcol_addSeasonProb(imgcol); 
  imgcol_year = pkg_trend.aggregate_prop(imgcol, "year", 'mean');
  pkg_trend.aggregate_prop(ImgCol, prop, reducer, delta)

• linearTrend, pkg_trend.linearTrend(ImgCol, robust)

4. Export data

// Load package
var pkg_export = require('users/kongdd/public:pkg_export.js');

If you need to download in batch, suggest combining with gee_monkey.

• ExportImg: Export ee.Image in degree, pkg_export.ExportImg(img, task, options)

• ExportImgCol: Export ee.ImageCollection in degree, pkg_export.ExportImgCol(ImgCol, dateList, options, prefix)

5. Palette

Show available palettes provided by pkg_vis. This function is modified from Gena‘s package.

pkg_vis.showColors();

Figure 1. Available palettes.