Writing .npy (numpy binary format) from java
We've encountered the same problem a while ago and implemented both NPY and NPZ formats in Kotlin as part of the npy library.
The current version (0.2.0) has a number of limitations. Specifically, it doesn't support
- multidimensional arrays
- structured arrays
- unsigned integral types and some others.
Java code:
Path filePath = new File("my.npz").toPath();int[] values = {1, 2, 3, 4, 5, 6};int[] shape = {2, 3};try (NpzFile.Writer writer = NpzFile.write(filePath, true)) { writer.write("my-entry", values, shape);}Maven dependency:
<dependency> <groupId>org.jetbrains.bio</groupId> <artifactId>npy</artifactId> <version>0.3.3</version></dependency>
I don't think there is a library to do this but you could look at the specification, or possibly use the matlab format as an intermediate, for which there appears to be at least one java library:
http://www.mathworks.com/matlabcentral/fileexchange/10759-jmatio-matlabs-mat-file-io-in-java
I've never done this, but it might work for you and then you can read those files via:
http://docs.scipy.org/doc/scipy/reference/generated/scipy.io.loadmat.html