如何将 R 的 writeBin() 输出读入 Java？

Question

考虑以下 R 代码：

f <- file("test.txt", "wb")
writeBin(c(1.2, 2.3, 3.4), f)
close(f)

我在Java中编写了以下代码来尝试读取这些数据：

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.DataInputStream;
import java.io.PrintWriter;

public class readBinary {

    public static void main(String[] argv) throws IOException {
        DataInputStream fileIn = new DataInputStream(new FileInputStream(argv[0]));
        FileOutputStream fileOut = new FileOutputStream(argv[1]);
        PrintWriter fileOutWriter = new PrintWriter(fileOut);

        int rows = Integer.parseInt(argv[2]);
        int cols = Integer.parseInt(argv[3]);

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                fileOutWriter.print(fileIn.readDouble() + " ");
            }
            fileOutWriter.println();
        }
        fileOutWriter.close();
    }

}

在命令行中：

javac readBinary.java
java readBinary test.txt test_new.txt 3 1

test_new.txt 文件输出：

4.667261458438315E-62 
1.9035985662475526E185 
4.667261458387024E-62

所以 Java 没有正确地将其视为三双。

因此，请问，writeBin 的输出到底是什么，如何将其读入 Java 以便正确读入预期的数字？

Answer 1

Java 默认为大端。因此请尝试使用 writeBin(..., endian = "big")

f <- file("test.txt", "wb")
writeBin(c(1.2, 2.3, 3.4), f, endian = "big")
close(f)

如何将 R 的 writeBin() 输出读入 Java？

How to read in writeBin() output from R into Java?

java

r

binary-data