private void calculateVector() {
    /*
     * Notice that this tool assumes that each record in the shapefile is an
     * individual polygon. The feature can contain multiple parts only if it
     * has holes, i.e. islands. A multipart record cannot contain multiple
     * and seperate features. This is because it complicates the calculation
     * of feature area and perimeter.
     */

    amIActive = true;

    // Declare the variable.
    String inputFile = null;
    int progress;
    double featureArea = 0;
    double circleArea = 0;
    double radius = 0;
    int recNum;
    int j, i;
    double[][] vertices = null;
    CoordinateArraySequence coordArray;
    LinearRing ring;
    MinimumBoundingCircle mbc;
    GeometryFactory factory = new GeometryFactory();
    Geometry geom;

    if (args.length <= 0) {
      showFeedback("Plugin parameters have not been set.");
      return;
    }

    inputFile = args[0];
    /*
     * args[1], args[2], and args[3] are ignored by the vector tool
     */

    // check to see that the inputHeader and outputHeader are not null.
    if (inputFile == null) {
      showFeedback("One or more of the input parameters have not been set properly.");
      return;
    }

    try {

      ShapeFile input = new ShapeFile(inputFile);
      double numberOfRecords = input.getNumberOfRecords();

      if (input.getShapeType().getBaseType() != ShapeType.POLYGON) {
        showFeedback("This function can only be applied to polygon type shapefiles.");
        return;
      }

      /* create a new field in the input file's database
      to hold the fractal dimension. Put it at the end
      of the database. */
      DBFField field = new DBFField();
      field = new DBFField();
      field.setName("RC_CIRCLE");
      field.setDataType(DBFField.DBFDataType.NUMERIC);
      field.setFieldLength(10);
      field.setDecimalCount(4);
      input.getAttributeTable().addField(field);

      // initialize the shapefile.
      ShapeType inputType = input.getShapeType();

      for (ShapeFileRecord record : input.records) {
        switch (inputType) {
          case POLYGON:
            whitebox.geospatialfiles.shapefile.Polygon recPolygon =
                (whitebox.geospatialfiles.shapefile.Polygon) (record.getGeometry());
            vertices = recPolygon.getPoints();
            coordArray = new CoordinateArraySequence(vertices.length);
            j = 0;
            for (i = 0; i < vertices.length; i++) {
              coordArray.setOrdinate(j, 0, vertices[i][0]);
              coordArray.setOrdinate(j, 1, vertices[i][1]);
              j++;
            }
            geom = factory.createMultiPoint(coordArray);
            mbc = new MinimumBoundingCircle(geom);
            radius = mbc.getRadius();
            circleArea = Math.PI * radius * radius;
            featureArea = recPolygon.getArea();
            break;
          case POLYGONZ:
            PolygonZ recPolygonZ = (PolygonZ) (record.getGeometry());
            vertices = recPolygonZ.getPoints();
            coordArray = new CoordinateArraySequence(vertices.length);
            j = 0;
            for (i = 0; i < vertices.length; i++) {
              coordArray.setOrdinate(j, 0, vertices[i][0]);
              coordArray.setOrdinate(j, 1, vertices[i][1]);
              j++;
            }
            geom = factory.createMultiPoint(coordArray);
            mbc = new MinimumBoundingCircle(geom);
            radius = mbc.getRadius();
            circleArea = Math.PI * radius * radius;
            featureArea = recPolygonZ.getArea();
            break;
          case POLYGONM:
            PolygonM recPolygonM = (PolygonM) (record.getGeometry());
            vertices = recPolygonM.getPoints();
            coordArray = new CoordinateArraySequence(vertices.length);
            j = 0;
            for (i = 0; i < vertices.length; i++) {
              coordArray.setOrdinate(j, 0, vertices[i][0]);
              coordArray.setOrdinate(j, 1, vertices[i][1]);
              j++;
            }
            geom = factory.createMultiPoint(coordArray);
            mbc = new MinimumBoundingCircle(geom);
            radius = mbc.getRadius();
            circleArea = Math.PI * radius * radius;
            featureArea = recPolygonM.getArea();
            break;
        }

        recNum = record.getRecordNumber() - 1;
        Object[] recData = input.getAttributeTable().getRecord(recNum);
        if (circleArea > 0) {
          recData[recData.length - 1] = new Double(1 - featureArea / circleArea);
        } else {
          recData[recData.length - 1] = new Double(0);
        }
        input.getAttributeTable().updateRecord(recNum, recData);

        if (cancelOp) {
          cancelOperation();
          return;
        }
        progress = (int) (record.getRecordNumber() / numberOfRecords * 100);
        updateProgress(progress);
      }

      // returning the database file will result in it being opened in the Whitebox GUI.
      returnData(input.getDatabaseFile());

    } 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();
    }
  }
  @Override
  public void run() {
    /*
     * This tool places the nodes (vertices) from a shapefile of polygons or
     * lines into a shapefile of Point ShapeType.
     */

    amIActive = true;
    String inputFile;
    String outputFile;
    int progress;
    int i, n;
    int numFeatures;
    int oneHundredthTotal;
    ShapeType shapeType, outputShapeType;
    GeometryFactory factory = new GeometryFactory();
    double distTolerance = 10;
    boolean loseNoFeatures = false;

    if (args.length <= 0) {
      showFeedback("Plugin parameters have not been set.");
      return;
    }

    inputFile = args[0];
    outputFile = args[1];
    distTolerance = Double.parseDouble(args[2]);
    loseNoFeatures = Boolean.parseBoolean(args[3]);

    // check to see that the inputHeader and outputHeader are not null.
    if ((inputFile == null) || (outputFile == null)) {
      showFeedback("One or more of the input parameters have not been set properly.");
      return;
    }

    try {
      // set up the input shapefile.
      ShapeFile input = new ShapeFile(inputFile);
      shapeType = input.getShapeType();

      // make sure that the shapetype is either a flavour of polyline or polygon.
      if (shapeType.getBaseType() != ShapeType.POLYGON
          && shapeType.getBaseType() != ShapeType.POLYLINE) {
        showFeedback("This tool only works with shapefiles of a polygon or line base shape type.");
        return;
      }

      // set up the output files of the shapefile and the dbf
      if (shapeType.getBaseType() == ShapeType.POLYGON) {
        outputShapeType = ShapeType.POLYGON;
      } else if (shapeType.getBaseType() == ShapeType.POLYLINE) {
        outputShapeType = ShapeType.POLYLINE;
      } else {
        showFeedback("This tool only works with shapefiles of a polygon or line base shape type.");
        return;
      }

      int numOutputFields = input.getAttributeTable().getFieldCount() + 1;
      int numInputFields = input.getAttributeTable().getFieldCount();
      DBFField[] inputFields = input.getAttributeTable().getAllFields();
      DBFField fields[] = new DBFField[numOutputFields];

      fields[0] = new DBFField();
      fields[0].setName("PARENT_ID");
      fields[0].setDataType(DBFField.DBFDataType.NUMERIC);
      fields[0].setFieldLength(10);
      fields[0].setDecimalCount(0);

      System.arraycopy(inputFields, 0, fields, 1, numInputFields);

      ShapeFile output = new ShapeFile(outputFile, outputShapeType, fields);

      numFeatures = input.getNumberOfRecords();
      oneHundredthTotal = numFeatures / 100;
      n = 0;
      progress = 0;
      com.vividsolutions.jts.geom.Geometry[] recJTS = null;
      int recordNum;
      for (ShapeFileRecord record : input.records) {
        recordNum = record.getRecordNumber();
        Object[] attData = input.getAttributeTable().getRecord(recordNum - 1);
        // featureNum++;
        recJTS = record.getGeometry().getJTSGeometries();

        ArrayList<com.vividsolutions.jts.geom.Geometry> geomList = new ArrayList<>();
        for (int a = 0; a < recJTS.length; a++) {
          geomList.add(recJTS[a]);
        }

        DouglasPeuckerSimplifier dps =
            new DouglasPeuckerSimplifier(factory.buildGeometry(geomList));
        dps.setDistanceTolerance(distTolerance);
        com.vividsolutions.jts.geom.Geometry outputGeom = dps.getResultGeometry();

        if (outputGeom.isEmpty() && loseNoFeatures) {
          outputGeom = factory.buildGeometry(geomList);
        }
        if (!outputGeom.isEmpty()) {
          for (int a = 0; a < outputGeom.getNumGeometries(); a++) {
            // parentRecNum = 0;
            com.vividsolutions.jts.geom.Geometry g = outputGeom.getGeometryN(a);
            if (g instanceof com.vividsolutions.jts.geom.Polygon && !g.isEmpty()) {
              com.vividsolutions.jts.geom.Polygon p = (com.vividsolutions.jts.geom.Polygon) g;
              ArrayList<ShapefilePoint> pnts = new ArrayList<>();
              int[] parts = new int[p.getNumInteriorRing() + 1];

              Coordinate[] buffCoords = p.getExteriorRing().getCoordinates();
              if (!Topology.isLineClosed(buffCoords)) {
                System.out.println("Exterior ring not closed.");
              }
              if (Topology.isClockwisePolygon(buffCoords)) {
                for (i = 0; i < buffCoords.length; i++) {
                  pnts.add(new ShapefilePoint(buffCoords[i].x, buffCoords[i].y));
                }
              } else {
                for (i = buffCoords.length - 1; i >= 0; i--) {
                  pnts.add(new ShapefilePoint(buffCoords[i].x, buffCoords[i].y));
                }
              }

              for (int b = 0; b < p.getNumInteriorRing(); b++) {
                parts[b + 1] = pnts.size();
                buffCoords = p.getInteriorRingN(b).getCoordinates();
                if (!Topology.isLineClosed(buffCoords)) {
                  System.out.println("Interior ring not closed.");
                }
                if (Topology.isClockwisePolygon(buffCoords)) {
                  for (i = buffCoords.length - 1; i >= 0; i--) {
                    pnts.add(new ShapefilePoint(buffCoords[i].x, buffCoords[i].y));
                  }
                } else {
                  for (i = 0; i < buffCoords.length; i++) {
                    pnts.add(new ShapefilePoint(buffCoords[i].x, buffCoords[i].y));
                  }
                }
              }

              PointsList pl = new PointsList(pnts);
              whitebox.geospatialfiles.shapefile.Polygon wbPoly =
                  new whitebox.geospatialfiles.shapefile.Polygon(parts, pl.getPointsArray());
              Object[] rowData = new Object[numOutputFields];
              rowData[0] = new Double(recordNum - 1);
              System.arraycopy(attData, 0, rowData, 1, numInputFields);
              output.addRecord(wbPoly, rowData);
            } else if (g instanceof com.vividsolutions.jts.geom.LineString && !g.isEmpty()) {
              LineString ls = (LineString) g;
              ArrayList<ShapefilePoint> pnts = new ArrayList<>();

              int[] parts = {0};

              Coordinate[] coords = ls.getCoordinates();
              for (i = 0; i < coords.length; i++) {
                pnts.add(new ShapefilePoint(coords[i].x, coords[i].y));
              }

              PointsList pl = new PointsList(pnts);
              whitebox.geospatialfiles.shapefile.PolyLine wbGeometry =
                  new whitebox.geospatialfiles.shapefile.PolyLine(parts, pl.getPointsArray());
              Object[] rowData = new Object[numOutputFields];
              rowData[0] = new Double(recordNum - 1);
              System.arraycopy(attData, 0, rowData, 1, numInputFields);
              output.addRecord(wbGeometry, rowData);
            }
          }
        }
        n++;
        if (n >= oneHundredthTotal) {
          n = 0;
          if (cancelOp) {
            cancelOperation();
            return;
          }
          progress++;
          updateProgress(progress);
        }
      }

      output.write();

      // returning a header file string displays the image.
      updateProgress("Displaying vector: ", 0);
      returnData(outputFile);

    } 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();
    }
  }