/// <summary> /// Inverse Distance Weighting Interpolation /// </summary> /// <param name="InPointsPath">Input point shapefile path to interpolate</param> /// <param name="InValueFieldIndex">Input field index where interpolation value is stored</param> /// <param name="OutGridPath">Output grid path where interpolation is stored</param> /// <param name="CellSize">Cell Size for output grid. Default lower of points extent height or width divided by 250</param> /// <param name="Power">Power variable for IDW algorithm. 0 lt p lt 1 will give sharp changes. >1 will give smoother. Default 2.</param> /// <param name="NeighborhoodType">Variable is a variable number of nearest points. Fixed is all points in a fixed distance</param> /// <param name="NeighborhoodCount">Variable Count is either number of nearest points to use. Fixed Count is minimum points needed to find valid interpolation</param> /// <param name="NeighborhoodDistance">Variable Distance is a maximum distance of nearest points. Fixed Distance is distance to use to select points</param> /// <param name="callback">A callback for progress information</param> public static void IDW(string InPointsPath, int InValueFieldIndex, string OutGridPath, double CellSize, double Power, IDWNeighborhoodType NeighborhoodType, int NeighborhoodCount, double NeighborhoodDistance, MapWinGIS.ICallback callback) { int newperc = 0, oldperc = 0; KDTreeDLL.KDTree pointsTree; double[][] Points; double[] PointVals; string proj, projUnits; MapWinGIS.Extents pointsExtents; CachePoints(InPointsPath, InValueFieldIndex, out pointsTree, out Points, out PointVals, out proj, out projUnits, out pointsExtents, callback); MapWinGIS.Grid outGrid; DataManagement.DeleteGrid(ref OutGridPath); double NoDataValue = -32768; CreateGridFromExtents(pointsExtents, CellSize, proj, NoDataValue, OutGridPath, out outGrid); //Cycle grid and find interpolated value for each cell int nr = outGrid.Header.NumberRows; int nc = outGrid.Header.NumberCols; double sumWeight, sumWeightAndVal, projX, projY; int[] neighbors; double[] CellPoint; newperc = 0; oldperc = 0; for (int row = 0; row < nr; row++) { newperc = Convert.ToInt32((Convert.ToDouble(row) / Convert.ToDouble(nr)) * 100); if (callback != null) { callback.Progress("Status", newperc, "IDW Row " + row.ToString() + "/" + nr.ToString()); } oldperc = newperc; newperc = 0; oldperc = 0; for (int col = 0; col < nc; col++) { outGrid.CellToProj(col, row, out projX, out projY); CellPoint = new double[2]; CellPoint[0] = projX; CellPoint[1] = projY; if (GetIDWNeighbors(CellPoint, ref pointsTree, ref Points, out neighbors, NeighborhoodType, NeighborhoodCount, NeighborhoodDistance, projUnits) == 0) { sumWeightAndVal = 0; sumWeight = 0; for (int i = 0; i < neighbors.Length; i++) { sumWeightAndVal += GetIDWeight(CellPoint, Points[neighbors[i]], projUnits, Power) * PointVals[neighbors[i]]; sumWeight += GetIDWeight(CellPoint, Points[neighbors[i]], projUnits, Power); } outGrid.set_Value(col, row, (sumWeightAndVal / sumWeight)); } } } outGrid.Save(OutGridPath, MapWinGIS.GridFileType.UseExtension, null); outGrid.Close(); if (callback != null) { callback.Progress("Status", 0, ""); } }
/// <summary> /// Inverse Distance Weighting Interpolation /// </summary> /// <param name="InPointsPath">Input point shapefile path to interpolate</param> /// <param name="InValueFieldIndex">Input field index where interpolation value is stored</param> /// <param name="OutGridPath">Output grid path where interpolation is stored</param> /// <param name="CellSize">Cell Size for output grid. Default lower of points extent height or width divided by 250</param> /// <param name="Power">Power variable for IDW algorithm. 0 lt p lt 1 will give sharp changes. >1 will give smoother. Default 2.</param> /// <param name="NeighborhoodType">Variable is a variable number of nearest points. Fixed is all points in a fixed distance</param> /// <param name="NeighborhoodCount">Variable Count is either number of nearest points to use. Fixed Count is minimum points needed to find valid interpolation</param> /// <param name="NeighborhoodDistance">Variable Distance is a maximum distance of nearest points. Fixed Distance is distance to use to select points</param> /// <param name="callback">A callback for progress information</param> public static void IDWBrute(string InPointsPath, int InValueFieldIndex, string OutGridPath, double CellSize, double Power, IDWNeighborhoodType NeighborhoodType, int NeighborhoodCount, double NeighborhoodDistance, MapWinGIS.ICallback callback) { int newperc = 0, oldperc = 0; List <InterpolationPoint> pointsCache; string proj, projUnits; MapWinGIS.Extents pointsExtents; CachePointsBrute(InPointsPath, InValueFieldIndex, out pointsCache, out proj, out projUnits, out pointsExtents, callback); MapWinGIS.Grid outGrid; DataManagement.DeleteGrid(ref OutGridPath); double NoDataValue = -32768; CreateGridFromExtents(pointsExtents, CellSize, proj, NoDataValue, OutGridPath, out outGrid); //Cycle grid and find interpolated value for each cell List <InterpolationPoint> neighbors; InterpolationPoint cellPoint; int nr = outGrid.Header.NumberRows; int nc = outGrid.Header.NumberCols; double sumWeight, sumWeightAndVal; newperc = 0; oldperc = 0; for (int row = 0; row < nr; row++) { newperc = Convert.ToInt32((Convert.ToDouble(row) / Convert.ToDouble(nr)) * 100); if (callback != null) { callback.Progress("Status", newperc, "IDW Row " + row); } newperc = 0; oldperc = 0; for (int col = 0; col < nc; col++) { newperc = Convert.ToInt32((Convert.ToDouble(col) / Convert.ToDouble(nc)) * 100); if ((newperc > oldperc)) { if (callback != null) { callback.Progress("Status", newperc, "IDW Row " + row.ToString() + " Col " + col.ToString()); } oldperc = newperc; } cellPoint = new InterpolationPoint(); outGrid.CellToProj(col, row, out cellPoint.X, out cellPoint.Y); GetIDWNeighborsBrute(cellPoint, ref pointsCache, out neighbors, NeighborhoodType, NeighborhoodCount, NeighborhoodDistance, projUnits); sumWeightAndVal = 0; sumWeight = 0; foreach (InterpolationPoint npoint in neighbors) { sumWeightAndVal += GetIDWeightBrute(cellPoint, npoint, projUnits, Power) * npoint.Value; sumWeight += GetIDWeightBrute(cellPoint, npoint, projUnits, Power); } outGrid.set_Value(col, row, (sumWeightAndVal / sumWeight)); } } outGrid.Save(OutGridPath, MapWinGIS.GridFileType.UseExtension, null); outGrid.Close(); }
/// <summary> /// Creates a new grid containing data from the input grid that /// falls within the polygon boundary. /// </summary> /// <param name="inputGF">Full path to the input grid file.</param> /// <param name="poly">The 2D polygon used for clipping the input grid.</param> /// <param name="resultGF">Full path to where the resulting grid will be saved.</param> /// <param name="clipToExtents">True if clipping to polygon extents rather than actual polygon shape.</param> /// <returns>True if clipping was successful, false if an error occurs.</returns> public static bool ClipGridWithPolygon(ref string inputGF, ref MapWinGIS.Shape poly, ref string resultGF, bool clipToExtents) { MapWinUtility.Logger.Dbg("ClipGridWithPolygon(inputGF: " + inputGF + ",\n" + " poly: " + Macro.ParamName(poly) + ",\n" + " resultGF: " + resultGF + ",\n" + " clipToExtents: " + clipToExtents.ToString()); Error.ClearErrorLog(); // System.Diagnostics.PerformanceCounter ramCounter; // ramCounter = new PerformanceCounter("Memory", "Available Bytes"); // float availableRAM = ramCounter.NextValue(); bool inRAM = true; //open grid to get info and traverse through points MapWinGIS.Grid grid = new MapWinGIS.GridClass(); //check memory availability // availableRAM = ramCounter.NextValue();//amount of RAM in bytes // Debug.WriteLine("available RAM: " + availableRAM.ToString() + " bytes"); // System.IO.FileInfo fileInfo = new FileInfo(inputGF); // long fileSize = fileInfo.Length; //size of file in bytes // Debug.WriteLine("file size: " + fileSize.ToString() + " bytes"); // if(fileSize*2 < availableRAM) // {//go ahead and load grid into memory // inRAM = true; // } // else // { // inRAM = false; // } if (grid.Open(inputGF, MapWinGIS.GridDataType.UnknownDataType, inRAM, MapWinGIS.GridFileType.UseExtension, null) == false) { gErrorMsg = "Error occurred while trying to open grid: " + grid.get_ErrorMsg(grid.LastErrorCode); Error.SetErrorMsg(gErrorMsg); Debug.WriteLine(gErrorMsg); MapWinUtility.Logger.Dbg(gErrorMsg); return(false); } int numCols = grid.Header.NumberCols; int numRows = grid.Header.NumberRows; double cellWidth = grid.Header.dX; double cellHeight = grid.Header.dY; double xllCenter = grid.Header.XllCenter; double yllCenter = grid.Header.YllCenter; //now calculate the UNCOMPRESSED grid file size: long inputGFSize = numCols * numRows * 8; //find the grid extents double minX, maxX, minY, maxY; minX = xllCenter - (cellWidth / 2); maxX = xllCenter + (cellWidth * (numCols - 1)) + (cellWidth / 2); minY = yllCenter - (cellHeight / 2); maxY = yllCenter + (cellHeight * (numRows - 1)) + (cellHeight / 2); //see if grid and poly extents cross: double polyMinX = poly.Extents.xMin; double polyMaxX = poly.Extents.xMax; double polyMinY = poly.Extents.yMin; double polyMaxY = poly.Extents.yMax; bool boundsIntersect = Globals.CheckBounds(minX, maxX, minY, maxY, polyMinX, polyMaxX, polyMinY, polyMaxY); if (boundsIntersect == false) { grid.Close(); gErrorMsg = "Polygon and Grid boundaries do not overlap."; Error.SetErrorMsg(gErrorMsg); Debug.WriteLine(gErrorMsg); MapWinUtility.Logger.Dbg(gErrorMsg); return(false); } double newXll, newYll, firstXPt, firstYPt; int newNumCols, newNumRows, firstCol, firstRow; //check if polygon extents are completely inside of grid extents if ((polyMinX >= minX && polyMinX <= maxX) && (polyMaxX >= minX && polyMaxX <= maxX) && (polyMinY >= minY && polyMinY <= maxY) && (polyMaxY >= minY && polyMaxY <= maxY)) { Debug.WriteLine("Poly extents are inside of grid extents."); minX = polyMinX; minY = polyMinY; maxX = polyMaxX; maxY = polyMaxY; //Find the new number of cols, rows, Xll and Yll values. int lastCol, lastRow; Globals.ProjToCell(minX, maxY, out firstCol, out firstRow, xllCenter, yllCenter, cellWidth, cellHeight, numRows); Globals.ProjToCell(maxX, minY, out lastCol, out lastRow, xllCenter, yllCenter, cellWidth, cellHeight, numRows); newNumCols = (lastCol - firstCol) + 1; newNumRows = (lastRow - firstRow) + 1; Debug.WriteLine("New numRows = " + newNumRows + " New numCols = " + newNumCols); Globals.CellToProj(firstCol, lastRow, out newXll, out newYll, xllCenter, yllCenter, cellWidth, cellHeight, numRows); Globals.CellToProj(firstCol, firstRow, out firstXPt, out firstYPt, xllCenter, yllCenter, cellWidth, cellHeight, numRows); } //check if grid extents are completely inside of polygon extents //note: there is really no purpose in this, as the new grid is the same //as the orgiginal grid....but we'll do it anyway. else if ((minX >= polyMinX && minX <= polyMaxX) && (maxX >= polyMinX && maxX <= polyMaxX) && (minY >= polyMinY && minY <= polyMaxY) && (maxY >= polyMinY && maxY <= polyMaxY)) { Debug.WriteLine("Grid extents are inside of polygon extents."); //keep min and max values the same....no need to change them. newNumCols = numCols; newNumRows = numRows; newXll = xllCenter; newYll = yllCenter; firstCol = 0; firstRow = 0; Globals.CellToProj(0, 0, out firstXPt, out firstYPt, xllCenter, yllCenter, cellWidth, cellHeight, numRows); } else //part of polygon lies outside of the grid, find intersecting boundary shape { Debug.WriteLine("Grid extents and polygon extents overlap."); //create a new shape out of the grid extents MapWinGIS.Shape gridEnvelope = new MapWinGIS.ShapeClass(); gridEnvelope.Create(MapWinGIS.ShpfileType.SHP_POLYGON); MapWinGIS.Point pt = new MapWinGIS.PointClass(); pt.x = minX; pt.y = maxY; int ptIndex = 0; gridEnvelope.InsertPoint(pt, ref ptIndex); pt = new MapWinGIS.PointClass(); pt.x = maxX; pt.y = maxY; ptIndex = 1; gridEnvelope.InsertPoint(pt, ref ptIndex); pt = new MapWinGIS.PointClass(); pt.x = maxX; pt.y = minY; ptIndex = 2; gridEnvelope.InsertPoint(pt, ref ptIndex); pt = new MapWinGIS.PointClass(); pt.x = minX; pt.y = minY; ptIndex = 3; gridEnvelope.InsertPoint(pt, ref ptIndex); pt = new MapWinGIS.PointClass(); pt.x = minX; pt.y = maxY; ptIndex = 4; gridEnvelope.InsertPoint(pt, ref ptIndex); //create the final bounding envelope which is //the intersection of the polygon and grid envelope: MapWinGIS.Shape envelope = new MapWinGIS.ShapeClass(); envelope.Create(MapWinGIS.ShpfileType.SHP_POLYGON); envelope = SpatialOperations.Intersection(gridEnvelope, poly); if (envelope.numPoints == 0) { gErrorMsg = "Problem creating the bounding envelope. Aborting ClipGrid()."; Error.SetErrorMsg(gErrorMsg); Debug.WriteLine(gErrorMsg); MapWinUtility.Logger.Dbg(gErrorMsg); return(false); } //calculate how many rows and columns will exist within the new grid //that is: how many rows/cols fit within the bounding envelope. minX = envelope.Extents.xMin; minY = envelope.Extents.yMin; maxX = envelope.Extents.xMax; maxY = envelope.Extents.yMax; newNumCols = (int)(((maxX - minX) / cellWidth) + 0.5); newNumRows = (int)(((maxY - minY) / cellHeight) + 0.5); newXll = minX + (cellWidth / 2); newYll = minY + (cellHeight / 2); firstXPt = newXll; firstYPt = newYll + (cellHeight * (newNumRows - 1)); Globals.ProjToCell(firstXPt, firstYPt, out firstCol, out firstRow, xllCenter, yllCenter, cellWidth, cellHeight, numRows); //done using COM objects, release them while (Marshal.ReleaseComObject(pt) != 0) { ; } pt = null; while (Marshal.ReleaseComObject(gridEnvelope) != 0) { ; } gridEnvelope = null; while (Marshal.ReleaseComObject(envelope) != 0) { ; } envelope = null; } // Chris M 12/13/2006 for BugZilla 377 // Below code: // The grid header cannot be copied right across like that! The first line creates // a new grid header; the second line deletes the newly created grid header and // copies a reference to the original grid's header. Both grids then are using // the same header; and when the last lines set the XllCenter and YllCenter, // BOTH grids are updated with that information! A classic example of pointers gone wrong. //MapWinGIS.GridHeader resultHeader = new MapWinGIS.GridHeaderClass(); //resultHeader = grid.Header; //resultHeader.NodataValue = grid.Header.NodataValue; //resultHeader.NumberCols = newNumCols; //resultHeader.NumberRows = newNumRows; //resultHeader.XllCenter = newXll; //resultHeader.YllCenter = newYll; // The right way to do it: MapWinGIS.GridHeader resultHeader = new MapWinGIS.GridHeaderClass(); resultHeader.CopyFrom(grid.Header); // Not really needed due to CopyFrom: resultHeader.NodataValue = grid.Header.NodataValue; resultHeader.NumberCols = newNumCols; resultHeader.NumberRows = newNumRows; resultHeader.XllCenter = newXll; resultHeader.YllCenter = newYll; // Not really needed due to CopyFrom: resultHeader.dX = grid.Header.dX; // Not really needed due to CopyFrom: resultHeader.dY = grid.Header.dY; // Not really needed due to CopyFrom: resultHeader.Projection = grid.Header.Projection; //create the new grid object MapWinGIS.Grid resultGrid = new MapWinGIS.GridClass(); DataManagement.DeleteGrid(ref resultGF); //check memory availability // availableRAM = ramCounter.NextValue();//amount of RAM in bytes // Debug.WriteLine("available RAM: " + availableRAM.ToString() + " bytes"); long resultGFSize = newNumCols * newNumRows * 8; //projected size of grid in bytes // if(resultGFSize * 2 < availableRAM) // {//go ahead and load grid into memory // inRAM = true; // } // else // { // inRAM = false; // } if (resultGrid.CreateNew(resultGF, resultHeader, grid.DataType, grid.Header.NodataValue, inRAM, MapWinGIS.GridFileType.UseExtension, null) == false) { gErrorMsg = "Problem creating the result grid: " + resultGrid.get_ErrorMsg(resultGrid.LastErrorCode); Debug.WriteLine(gErrorMsg); Error.SetErrorMsg(gErrorMsg); MapWinUtility.Logger.Dbg(gErrorMsg); return(false); } //close the grids, we need to use the wrapper class now due to memory issues resultGrid.Save(resultGF, MapWinGIS.GridFileType.UseExtension, null); resultGrid.Close(); while (Marshal.ReleaseComObject(resultGrid) != 0) { ; } resultGrid = null; grid.Close(); while (Marshal.ReleaseComObject(grid) != 0) { ; } grid = null; //fill the result grid with values from the original grid try { Debug.WriteLine("newNumRows = " + newNumRows + " newNumCols = " + newNumCols); int rowClearCount = Globals.DetermineRowClearCount(newNumRows, newNumCols); Debug.WriteLine("Clearing COM resources every " + rowClearCount + " rows."); if (FillGrid(ref inputGF, ref resultGF, ref poly, newNumRows, newNumCols, rowClearCount, firstCol, firstRow, firstXPt, firstYPt, clipToExtents) == false) { MapWinUtility.Logger.Dbg("Error running FillGrid\n"); return(false); } } //end of try block catch (Exception e) { gErrorMsg = e.Message + e.ToString(); Debug.WriteLine(gErrorMsg); Error.SetErrorMsg(gErrorMsg); MapWinUtility.Logger.Dbg(gErrorMsg); return(false); } //NOTE: The need for trimGrid has been removed from this function. //It will always return the smallest possible grid because we //build it based on the intersection boundary. DataManagement.CopyGridLegend(inputGF, resultGF); MapWinUtility.Logger.Dbg("Finished ClipGridWithPolygon"); return(true); }