You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

108 lines
3.7 KiB

package mock.dataInput;
import mock.exceptions.InvalidPolarFileException;
import mock.model.Polars;
import shared.model.Bearing;
import java.io.*;
import java.util.ArrayList;
/**
* Responsible for parsing a polar data file, and creating a Polar data object.
*/
public class PolarParser {
/**
* Given a filename, this function parses it and generates a Polar object, which can be queried for polar information.
* @param filename The filename to load and read data from (loaded as a resource).
* @return A Polar table containing data from the given file.
*/
public static Polars parse(String filename) throws InvalidPolarFileException {
//Temporary table to return later.
Polars polarTable = new Polars();
//Open the file for reading.
InputStream fileStream = PolarParser.class.getClassLoader().getResourceAsStream(filename);
if (fileStream == null) {
throw new InvalidPolarFileException("Could not open polar data file: " + filename);
}
//Wrap it with buffered input stream to set encoding and buffer.
InputStreamReader in = null;
try {
in = new InputStreamReader(fileStream, "UTF-8");
} catch (UnsupportedEncodingException e) {
throw new InvalidPolarFileException("Unsupported encoding: UTF-8", e);
}
BufferedReader inputStream = new BufferedReader(in);
//We expect the polar data file to have the column headings:
// Tws, Twa0, Bsp0, Twa1, Bsp1, UpTwa, UpBsp, Twa2, Bsp2, Twa3, Bsp3, Twa4, Bsp4, Twa5, Bsp5, Twa6, Bsp6, DnTwa, DnBsp, Twa7, Bsp7
//and to have 7 rows of data.
//Angles are expected to be in degrees, and velocities in knots.
//We read data rows, and split them into arrays of elements.
ArrayList<String[]> dataRows = new ArrayList<>(7);
try {
//Heading row.
//We skip the heading row by reading it.
String headingRow = inputStream.readLine();
//Data rows.
while (inputStream.ready()) {
//Read line.
String dataRow = inputStream.readLine();
//Split line.
String[] dataElements = dataRow.split(",");
//Add to collection.
dataRows.add(dataElements);
}
} catch (IOException e) {
throw new InvalidPolarFileException("Could not read from polar data file: " + filename, e);
}
//Finished reading in data, now we need to construct polar rows and table from it.
//For each row...
int rowNumber = 0;
for (String[] row : dataRows) {
//For each pair of columns (the pair is angle, speed).
//We start at column 1 since column 0 is the wind speed column.
for (int i = 1; i < row.length; i += 2) {
//Add angle+speed=velocity estimate to polar table.
try {
//Add the polar value to the polar table
double windSpeedKnots = Double.parseDouble(row[0]);
double angleDegrees = Double.parseDouble(row[i]);
Bearing angle = Bearing.fromDegrees(angleDegrees);
double boatSpeedKnots = Double.parseDouble(row[i + 1]);
polarTable.addEstimate(windSpeedKnots, angle, boatSpeedKnots);
} catch (NumberFormatException e) {
throw new InvalidPolarFileException("Could not convert (Row,Col): (" + rowNumber + "," + i +") = " + row[i] + " to a double.", e);
}
}
//Increment row number.
rowNumber++;
}
return polarTable;
}
}