Package io.github.andreipunko.util

Class FileUtil

java.lang.Object

io.github.andreipunko.util.FileUtil

public class FileUtil
extends Object

Utilities to write text data to files. All textual output uses UTF-8. saveFunc(io.github.andreipunko.math.space.Interval, java.util.function.Function<java.lang.Double, java.lang.Double>, java.lang.String), save(Matrix2D, String, boolean), and PDE Solution methods (Solution.sUt(String, double[]), Solution.sUx(String, double[])) prefix a short # header and format numbers with formatDouble(double) (data comes from Solution.matrix()).

Method Summary

Modifier and Type	Method	Description
static String	formatDouble(double value)	Locale-independent numeric text for exports: US decimal point, %.17g (up to 17 significant digits).
static void	save(Matrix2D m, String fileName, boolean rotate)	Save matrix into file.
static void	saveFunc(Interval interval, Function<Double,Double> func, String fileName)	Save function y(x) on given interval into file.
static void	saveFunc(Interval timeInterval, Function<Double,Double> xFunc, Function<Double,Double> yFunc, String fileName)	Save function y(x) on given time interval into file for parameterized functions x(t) and y(t).
static void	serialize(StringBuilder sb, String fileName)	Save text data from StringBuilder instance into file using UTF-8 encoding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

formatDouble

public static String formatDouble(double value)

Locale-independent numeric text for exports: US decimal point, %.17g (up to 17 significant digits).

Parameters:

value - number to format

Returns:

formatted string suitable for text export files

serialize

public static void serialize(StringBuilder sb,
 String fileName)
                      throws IOException

Save text data from StringBuilder instance into file using UTF-8 encoding.

Parameters:

sb - StringBuilder instance

fileName - name of file (parent directories are created if they do not exist)

Throws:

IllegalArgumentException - if sb or fileName is null

IOException - if an I/O error occurs creating directories or writing the file

saveFunc

public static void saveFunc(Interval interval,
 Function<Double,Double> func,
 String fileName)
                     throws IOException

Save function y(x) on given interval into file. Lines starting with # describe columns; data rows use formatDouble(double).

Parameters:

interval - interval

func - function y = y(x)

fileName - name of file

Throws:

IllegalArgumentException - if interval, func or fileName is null

IOException - if an I/O error occurs writing the file

saveFunc

public static void saveFunc(Interval timeInterval,
 Function<Double,Double> xFunc,
 Function<Double,Double> yFunc,
 String fileName)
                     throws IOException

Save function y(x) on given time interval into file for parameterized functions x(t) and y(t). Lines starting with # describe columns; data rows use formatDouble(double).

Parameters:

timeInterval - time interval

xFunc - function x = x(t)

yFunc - function y = y(t)

fileName - name of file

Throws:

IllegalArgumentException - if any argument is null

IOException - if an I/O error occurs writing the file

save

public static void save(Matrix2D m,
 String fileName,
 boolean rotate)
                 throws IOException

Save matrix into file. Lines starting with # give dimensions and layout; data rows use formatDouble(double).

Parameters:

m - matrix to save

fileName - name of file

rotate - flag - rotate matrix or not before saving

Throws:

IllegalArgumentException - if m or fileName is null

IOException - if an I/O error occurs writing the file