/* * Copyright (C) 2011-2012 Dr. John Lindsay <jlindsay@uoguelph.ca> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package plugins; import java.util.Date; import whitebox.geospatialfiles.WhiteboxRaster; import whitebox.interfaces.WhiteboxPlugin; import whitebox.interfaces.WhiteboxPluginHost; /** * This tool is used to generate a flow accumulation grid (i.e., contributing area) using the FD8 algorithm (Freeman, 1991). * * @author Dr. John Lindsay email: jlindsay@uoguelph.ca */ public class FlowAccumFD8 implements WhiteboxPlugin { private WhiteboxPluginHost myHost = null; private String[] args; WhiteboxRaster DEM; WhiteboxRaster output; WhiteboxRaster tmpGrid; double threshold = 0; double noData = -32768; int[] dX = new int[]{1, 1, 1, 0, -1, -1, -1, 0}; int[] dY = new int[]{-1, 0, 1, 1, 1, 0, -1, -1}; double power = 1; double gridRes; // Constants private static final double LnOf2 = 0.693147180559945; /** * Used to retrieve the plugin tool's name. This is a short, unique name * containing no spaces. * * @return String containing plugin name. */ @Override public String getName() { return "FlowAccumFD8"; } /** * Used to retrieve the plugin tool's descriptive name. This can be a longer * name (containing spaces) and is used in the interface to list the tool. * * @return String containing the plugin descriptive name. */ @Override public String getDescriptiveName() { return "FD8 Flow Accumulation"; } /** * Used to retrieve a short description of what the plugin tool does. * * @return String containing the plugin's description. */ @Override public String getToolDescription() { return "Performs an FD8 flow accumulation operation on a " + "specified digital elevation model (DEM)."; } /** * Used to identify which toolboxes this plugin tool should be listed in. * * @return Array of Strings. */ @Override public String[] getToolbox() { String[] ret = {"FlowAccum"}; return ret; } /** * Sets the WhiteboxPluginHost to which the plugin tool is tied. This is the * class that the plugin will send all feedback messages, progress updates, * and return objects. * * @param host The WhiteboxPluginHost that called the plugin tool. */ @Override public void setPluginHost(WhiteboxPluginHost host) { myHost = host; } /** * Used to communicate feedback pop-up messages between a plugin tool and * the main Whitebox user-interface. * * @param feedback String containing the text to display. */ private void showFeedback(String message) { if (myHost != null) { myHost.showFeedback(message); } else { System.out.println(message); } } /** * Used to communicate a return object from a plugin tool to the main * Whitebox user-interface. * * @return Object, such as an output WhiteboxRaster. */ private void returnData(Object ret) { if (myHost != null) { myHost.returnData(ret); } } private int previousProgress = 0; private String previousProgressLabel = ""; /** * Used to communicate a progress update between a plugin tool and the main * Whitebox user interface. * * @param progressLabel A String to use for the progress label. * @param progress Float containing the progress value (between 0 and 100). */ private void updateProgress(String progressLabel, int progress) { if (myHost != null && ((progress != previousProgress) || (!progressLabel.equals(previousProgressLabel)))) { myHost.updateProgress(progressLabel, progress); } previousProgress = progress; previousProgressLabel = progressLabel; } /** * Used to communicate a progress update between a plugin tool and the main * Whitebox user interface. * * @param progress Float containing the progress value (between 0 and 100). */ private void updateProgress(int progress) { if (myHost != null && progress != previousProgress) { myHost.updateProgress(progress); } previousProgress = progress; } /** * Sets the arguments (parameters) used by the plugin. * * @param args An array of string arguments. */ @Override public void setArgs(String[] args) { this.args = args.clone(); } private boolean cancelOp = false; /** * Used to communicate a cancel operation from the Whitebox GUI. * * @param cancel Set to true if the plugin should be canceled. */ @Override public void setCancelOp(boolean cancel) { cancelOp = cancel; } private void cancelOperation() { showFeedback("Operation cancelled."); updateProgress("Progress: ", 0); } private boolean amIActive = false; /** * Used by the Whitebox GUI to tell if this plugin is still running. * * @return a boolean describing whether or not the plugin is actively being * used. */ @Override public boolean isActive() { return amIActive; } /** * Used to execute this plugin tool. */ @Override public void run() { amIActive = true; String inputHeader = null; String outputHeader = null; int row, col, x, y; float progress = 0; double slope; double z, z2; int i; double numInNeighbours; boolean flag = false; boolean logTransform = false; String outputType = null; if (args.length <= 0) { showFeedback("Plugin parameters have not been set."); return; } for (i = 0; i < args.length; i++) { if (i == 0) { inputHeader = args[i]; } else if (i == 1) { outputHeader = args[i]; } else if (i == 2) { power = Double.parseDouble(args[i]); if (power > 10) { power = 10; } } else if (i == 3) { outputType = args[i].toLowerCase(); } else if (i == 4) { logTransform = Boolean.parseBoolean(args[i]); } else if (i == 5) { if (!args[i].toLowerCase().contains("not specified")) { threshold = Double.parseDouble(args[i]); } else { threshold = -9999; } } } // check to see that the inputHeader and outputHeader are not null. if ((inputHeader == null) || (outputHeader == null)) { showFeedback("One or more of the input parameters have not been set properly."); return; } try { DEM = new WhiteboxRaster(inputHeader, "r"); int rows = DEM.getNumberRows(); int cols = DEM.getNumberColumns(); noData = DEM.getNoDataValue(); gridRes = DEM.getCellSizeX(); output = new WhiteboxRaster(outputHeader, "rw", inputHeader, WhiteboxRaster.DataType.FLOAT, 1); output.setPreferredPalette("blueyellow.pal"); output.setDataScale(WhiteboxRaster.DataScale.CONTINUOUS); output.setZUnits("dimensionless"); tmpGrid = new WhiteboxRaster(outputHeader.replace(".dep", "_temp.dep"), "rw", inputHeader, WhiteboxRaster.DataType.FLOAT, noData); tmpGrid.isTemporaryFile = true; // Calculate the number of inflowing neighbours to each cell. int loopNum = 1; updateProgress("Loop " + loopNum + ":", 0); for (row = 0; row < rows; row++) { for (col = 0; col < cols; col++) { z = DEM.getValue(row, col); if (z != noData) { numInNeighbours = 0; for (i = 0; i < 8; i++) { if (DEM.getValue(row + dY[i], col + dX[i]) > z) { numInNeighbours++; } } tmpGrid.setValue(row, col, numInNeighbours); } else { output.setValue(row, col, noData); } } if (cancelOp) { cancelOperation(); return; } progress = (float) (100f * row / (rows - 1)); updateProgress("Loop " + loopNum + ":", (int) progress); } boolean somethingDone; do { loopNum++; updateProgress("Loop " + loopNum + ":", 0); somethingDone = false; for (row = 0; row < rows; row++) { for (col = 0; col < cols; col++) { if (tmpGrid.getValue(row, col) == 0) { //there are no //remaining inflowing neighbours, send it's current //flow accum val downslope FD8Accum(row, col); somethingDone = true; } } if (cancelOp) { cancelOperation(); return; } progress = (float) (100f * row / (rows - 1)); updateProgress("Loop " + loopNum + ":", (int) progress); } } while (somethingDone); loopNum++; updateProgress("Loop " + loopNum + ":", 0); if (outputType.equals("specific catchment area (sca)")) { for (row = 0; row < rows; row++) { for (col = 0; col < cols; col++) { z = DEM.getValue(row, col); if (z != noData) { output.setValue(row, col, output.getValue(row, col) * gridRes); } } if (cancelOp) { cancelOperation(); return; } progress = (float) (100f * row / (rows - 1)); updateProgress("Loop " + loopNum + ":", (int) progress); } } else if (outputType.equals("total catchment area")) { double gridCellArea = gridRes * gridRes; for (row = 0; row < rows; row++) { for (col = 0; col < cols; col++) { z = output.getValue(row, col); if (z != noData) { output.setValue(row, col, output.getValue(row, col) * gridCellArea); } } if (cancelOp) { cancelOperation(); return; } progress = (float) (100f * row / (rows - 1)); updateProgress("Loop " + loopNum + ":", (int) progress); } } if (logTransform) { for (row = 0; row < rows; row++) { for (col = 0; col < cols; col++) { z = output.getValue(row, col); if (z != noData) { output.setValue(row, col, Math.log(output.getValue(row, col))); } } if (cancelOp) { cancelOperation(); return; } progress = (float) (100f * row / (rows - 1)); updateProgress("Loop " + loopNum + ":", (int) progress); } } else { output.setNonlinearity(0.2); } output.addMetadataEntry("Created by the " + getDescriptiveName() + " tool."); output.addMetadataEntry("Created on " + new Date()); DEM.close(); tmpGrid.close(); output.close(); // returning a header file string displays the image. returnData(outputHeader); } catch (OutOfMemoryError oe) { myHost.showFeedback("An out-of-memory error has occurred during operation."); } catch (Exception e) { myHost.showFeedback("An error has occurred during operation. See log file for details."); myHost.logException("Error in " + getDescriptiveName(), e); } finally { updateProgress("Progress: ", 0); // tells the main application that this process is completed. amIActive = false; myHost.pluginComplete(); } } int currentDepth; final int maxDepth = 1000; private void FD8Accum(int row, int col) { double flowAccumVal = output.getValue(row, col); double proportion = 0; double totalRelief = 0; int a, b; byte c; double z1 = DEM.getValue(row, col); double z2; double z; currentDepth++; if (currentDepth > maxDepth) { return; } tmpGrid.setValue(row, col, -1); if (threshold > flowAccumVal || threshold == -9999) { for (c = 0; c < 8; c++) { a = col + dX[c]; b = row + dY[c]; z2 = DEM.getValue(b, a); if (z1 > z2 && z2 != noData) { totalRelief += Math.pow((z1 - z2), power); } } for (c = 0; c < 8; c++) { a = col + dX[c]; b = row + dY[c]; z2 = DEM.getValue(b, a); if (z1 > z2 && z2 != noData) { proportion = Math.pow((z1 - z2), power) / totalRelief; z = output.getValue(b, a); output.setValue(b, a, z + flowAccumVal * proportion); tmpGrid.setValue(b, a, tmpGrid.getValue(b, a) - 1); if (tmpGrid.getValue(b, a) == 0) { FD8Accum(b, a); } } } } else { //use a D8 method //find the the steepest downslope neighbour double slope; double maxSlope = -999999999; double diagGridRes = gridRes * Math.sqrt(2); double dist = diagGridRes; double flowDir = 255; for (c = 0; c < 8; c++) { a = col + dX[c]; b = row + dY[c]; z2 = DEM.getValue(b, a); if (z1 > z2 && z2 != noData) { slope = (z1 - z2) / dist; if (slope > maxSlope) { maxSlope = slope; flowDir = c; } } if (dist == gridRes) { dist = diagGridRes; } else { dist = gridRes; } } for (c = 0; c < 8; c++) { a = col + dX[c]; b = row + dY[c]; z2 = DEM.getValue(b, a); if (z1 > z2 && z2 != noData) { if (c == flowDir) { proportion = 1; } else { proportion = 0; } output.setValue(b, a, output.getValue(b, a) + flowAccumVal * proportion); tmpGrid.setValue(b, a, tmpGrid.getValue(b, a) - 1); if (tmpGrid.getValue(b, a) == 0) { FD8Accum(b, a); } } } } currentDepth--; } }