Clarinetist :
Consider the following R code:
f <- file("test.txt", "wb")
writeBin(c(1.2, 2.3, 3.4), f)
close(f)
I have written the following code in Java to try to read these data:
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();
}
}
In the command line:
javac readBinary.java
java readBinary test.txt test_new.txt 3 1
The test_new.txt file outputs:
4.667261458438315E-62
1.9035985662475526E185
4.667261458387024E-62
So Java is not picking this up as three doubles correctly.
Thus, I ask, what exactly is the output of writeBin, and how could it be read into Java so that the intended numbers are read in correctly?
Andrey Shabalin :
Java in big-endian by default. Thus please try using writeBin(..., endian = "big")
f <- file("test.txt", "wb")
writeBin(c(1.2, 2.3, 3.4), f, endian = "big")
close(f)
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