The OP is from 2011. So as of end of 2015 I would like mention that there is a new kid in town which claims to be numpy for java -> nd4j]. The nice thing is that nd4j is an abstraction layer on top of different libraries like blas. Depending on the size of your matrices there are underlying implementations twice as fast as numpy or jblas. And your code is real platform independent.

Answer from KIC on Stack Overflow
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Stack Overflow
stackoverflow.com › questions › 8375558 › java-equivalent-for-the-numpy-multi-dimensional-object
multidimensional array - Java equivalent for the Numpy multi-dimensional object - Stack Overflow
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The OP is from 2011. So as of end of 2015 I would like mention that there is a new kid in town which claims to be numpy for java -> nd4j]. The nice thing is that nd4j is an abstraction layer on top of different libraries like blas. Depending on the size of your matrices there are underlying implementations twice as fast as numpy or jblas. And your code is real platform independent.

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The library Vectorz (https://github.com/mikera/vectorz) offers a fully featured NDArray that is broadly equivalent in functionality to Numpy's NDArray, i.e. it offers the fullowing features:

  • Arbitrary N-dimensional arrays of numeric values (in this case, Java doubles)
  • Lightweight views using strided access for efficient slicing
  • A broad range of mathematical operations with effiecient implementations

It's also very fast: it is much faster then NumPy for most operations, although NumPy may still be faster for certain large matrix operations because it uses the native BLAS libraries to accelerate these.

Here's the NDArray class itself:

https://github.com/mikera/vectorz/blob/develop/src/main/java/mikera/arrayz/NDArray.java

Disclaimer: I'm the author of Vectorz

Multidimension Array In Java
Multi-dimensional arrays in Java
java - multidimensional arrays and methods
python - Handling Multidimensional Arrays in Numpy
python - Numpy Multidimensional Array
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InfoWorld
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December 8, 2020 - In Python, the standard library for NDArrays is called NumPy. However, there is no equivalent standard library in Java. One offering for Java developers interested in working with NDArrays is AWS’s Deep Java Library (DJL).
Discussions
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In the Python world, if I have some number crunching to do, I use NumPy and it's friends like Matplotlib. Now I have an Android/Java application and the need arises to crunch some numbers and I am More on softwarerecs.stackexchange.com
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Python only needs NumPy because NumPy performs its tasks directly in C, which is way faster than Python. Java doesn't need something like that, as it's a partially compiled language with many parts of the base modules written directly in Assembly. Therefore the equivalent for NumPy in Java would simply be the standard Java math module More on reddit.com
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https://github.com/cardillo/joinery

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Beyondthelines
beyondthelines.net › machine-learning › nd4j-numpy-for-the-jvm
Nd4j – Numpy for the JVM – Beyond the lines
JavaCPP also manages the off-heap memory where the data (tensors/matrices/…) are stored. Now that we’re all setup let’s see how the code looks like with a very basic example: ... val ones = Nd4j.create(3, 2) // 3 x 2 matrix filled with 0s ones.addi(1.0) // addi stands for add in-place println(s"ones: \n$ones") val matrix = Nd4j.create( Array(1.0, 2.0, 3.0, 4.0, 5.0, 6.0), // the values Array(3, 2), // dimensions: 3 x 2 'c' // 'c' c-style (row major) ) println(s"matrix: \n$matrix") val result = ones.transpose mmul matrix // onesT x matrix println(s"result: \n$result")
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Stack Exchange
softwarerecs.stackexchange.com › questions › 43154 › java-equivalent-to-numpy
math - Java equivalent to NumPy - Software Recommendations Stack Exchange
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The nd4j.org API tries to mimic the semantics of Numpy, Matlab and scikit-learn. deeplearning4j.org is based on nd4j.

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NM Dev is a Java numerical library (commercial, community and academical licenses ).

The open source of it is available at: https://github.com/nmdev2020/SuanShu

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Reddit
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r/learnjava on Reddit: NumPy equivalent for Java?
November 4, 2021 -

Is the a NumPy equivalent for Java?

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Python only needs NumPy because NumPy performs its tasks directly in C, which is way faster than Python. Java doesn't need something like that, as it's a partially compiled language with many parts of the base modules written directly in Assembly. Therefore the equivalent for NumPy in Java would simply be the standard Java math module
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I don't think there is a single Java library that covers so much functionality. I've seen Parallel Colt library originated at CERN, it should contain at least the basic pieces.
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NumPy
numpy.org › doc › stable › reference › generated › numpy.ones_like.html
numpy.ones_like — NumPy v2.5 Manual
Return an array of ones with the same shape and type as a given array.
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DEV Community
dev.to › darius_nica › introducing-numpy4j-bringing-numpy-style-computing-tojava-3gha
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Stack Overflow
stackoverflow.com › questions › 57536534 › is-there-any-java-equivalent-of-numpy
python - Is there any Java equivalent of NumPy? - Stack Overflow
In anyway, you can find here an example of using numpy from Java using MetaFFI.
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Reddit
reddit.com › r/learnjava › what is comparable to python pandas and numpy in java?
r/learnjava on Reddit: What is comparable to Python Pandas and Numpy in Java?
October 12, 2020 -

I'm looking to build an application which connects to a SQL Server database, manipulates data pulled from it, reads an excel file, manipulates data inside it and writes a CSV file (to be read by some other application).

I've created a program that does exactly this in Python using pandas and numpy.

What are comparable Java packages/modules?

Side note: I know very little Java and figure this could be a good first project for me.

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https://github.com/cardillo/joinery

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Reddit
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r/java on Reddit: NumPy equivalent for Java?
November 4, 2021 - it does have some datatypes in (such as biginteger) but the the collections (similar to some found in numpy) are in java.util
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NumPy
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>>> y = np.arange(3, dtype=float) >>> y array([0., 1., 2.]) >>> np.ones_like(y) array([1., 1., 1.])
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Imagej
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Reddit
reddit.com › r/java › what are the best java libraries for data analysis and machine learning?
r/java on Reddit: What are the best Java libraries for data analysis and machine learning?
December 18, 2017 -

Basically I am looking for equivalent of Python’s NumPy, SciPy, pandas, scikit-learn and Keras.

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JSAT is totally the indisputably best ML library for Java. I'm not 1000% biased because I wrote it or anything.

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Some are not Java but run-on the JVM

https://spark.apache.org/

https://software.intel.com/en-us/intel-daal

http://mxnet.incubator.apache.org/

https://mahout.apache.org/

https://flink.apache.org/

http://ranksys.org/

https://deeplearning4j.org/

https://www.h2o.ai/

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GitHub
github.com › JosephCottam › Numpy4J
GitHub - JosephCottam/Numpy4J: Interface Java with Numpy. Try to be reasonable. · GitHub
What works: If you make an NPArray (that's the Java class that represents a Numpy array), you can execute max, min, log and array-array multiply. For log and multiply, the resulting NPArray is actually backed by memory that numpy allocated for ...
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Medium
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