{"id":23158763,"url":"https://github.com/greendelta/npy","last_synced_at":"2025-04-04T18:40:59.214Z","repository":{"id":68566970,"uuid":"401998903","full_name":"GreenDelta/npy","owner":"GreenDelta","description":"npy is a Java 11+ library for reading and writing arrays in the NumPy NPY and NPZ format.","archived":false,"fork":false,"pushed_at":"2022-07-12T14:34:13.000Z","size":207,"stargazers_count":1,"open_issues_count":0,"forks_count":1,"subscribers_count":3,"default_branch":"master","last_synced_at":"2025-02-10T03:46:22.493Z","etag":null,"topics":["java","npy","npy-files"],"latest_commit_sha":null,"homepage":"","language":"Java","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mpl-2.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/GreenDelta.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null}},"created_at":"2021-09-01T09:09:42.000Z","updated_at":"2023-12-21T09:08:25.000Z","dependencies_parsed_at":"2023-09-26T02:31:53.020Z","dependency_job_id":null,"html_url":"https://github.com/GreenDelta/npy","commit_stats":{"total_commits":127,"total_committers":1,"mean_commits":127.0,"dds":0.0,"last_synced_commit":"edc9889741f012495d9d840c6a455498345bc830"},"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/GreenDelta%2Fnpy","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/GreenDelta%2Fnpy/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/GreenDelta%2Fnpy/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/GreenDelta%2Fnpy/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/GreenDelta","download_url":"https://codeload.github.com/GreenDelta/npy/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":247234841,"owners_count":20905852,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["java","npy","npy-files"],"created_at":"2024-12-17T22:27:27.535Z","updated_at":"2025-04-04T18:40:59.188Z","avatar_url":"https://github.com/GreenDelta.png","language":"Java","funding_links":[],"categories":[],"sub_categories":[],"readme":"# npy\n`npy` is a Java 11+ library for reading and writing arrays in the NumPy \n[NPY and NPZ](https://numpy.org/devdocs/reference/generated/numpy.lib.format.html)\nformat.\n\n__Features__\n\n* written in pure Java 11 with no other dependencies\n* supports reading arrays of 8-, 16-, 32-, and 64-bit signed and unsigned\n  integers as well as booleans and 16-, 32-, and 64-bit floating point numbers\n* supports writing arrays of all primitive Java types:\n  `boolean`, `byte`, `short`, `int`, `long`, `float`, `double`, `char`\n* supports all NPY format versions (1, 2, and 3)\n* provides a simple `NpyArray` interface for all array types and conversions as\n  well as a utility class `Array2d` for reading matrix data\n\n__Limitations__\n\n* only supports types listed above, no tuples, structs, etc.\n* needs more tests, version is `0.0.1`\n\n__Alternatives__\n* If a Kotlin library is fine for you, checkout\n  [npy from JetBrains-Research](https://github.com/JetBrains-Research/npy)\n* Scala? maybe [this](https://github.com/priimak/scala-data)\n\n\n## Installation\nThe latest version is available on the \n[Maven Central](https://search.maven.org/artifact/org.openlca/npy). If you are\nusing Maven add the following dependency to your `pom.xml`:\n\n```xml\n\u003cdependency\u003e\n  \u003cgroupId\u003eorg.openlca\u003c/groupId\u003e\n  \u003cartifactId\u003enpy\u003c/artifactId\u003e\n  \u003cversion\u003e0.0.1\u003c/version\u003e\n\u003c/dependency\u003e\n```\n\nFor Gradle, add this to your `build.gradle`:\n\n```groovy\ndependencies {\n  compile 'org.openlca:npy:0.0.1'\n}\n```\n\n\n## Examples\n\nReading and writing an NPY file:\n\n```java\nvar array = Npy.read(file);\nNpy.write(otherFile, array);\n```\n\nType checks and type conversions:\n\n```java\nif (array.isDoubleArray()) {\n  var doubles = array.asDoubleArray();\n  for (double value : doubles.values()) {\n    // ...    \n  }\n  var ints = doubles.asIntArray();  // may result in data loss\n  for (int values : ints.values()) {\n    // ...\n  }\n  var longs = ints.asLongArray();\n  // ...\n}\n```\n\nReading and writing NPZ files:\n\n```java\nfor (var entry : Npz.entries(npzFile)) {\n  var array = Npz.load(npzFile, entry);\n  // ...\n}\nNpz.create(npzFile, out -\u003e {\n  Npz.write(out, \"shape.npy\", shape);\t\n  Npz.write(out, \"values.npy\", values);\n  // ...\n});\n```\n\n\nReading parts of a file; e.g. the first 100 elements:\n\n```java\nvar range = Npy.readRange(file, numberOfElements, offset);\n```\n\nUsing the `Array2d` utilities for 2-dimensional arrays (matrices):\n\n```java\nNpy.use(file, (chan, head) -\u003e {\n  var row42 = Array2d.readRow(chan, head, 142);\n  var col42 = Array2d.readColumn(chan, head, 42);\n  // ...\n});\n```\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fgreendelta%2Fnpy","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fgreendelta%2Fnpy","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fgreendelta%2Fnpy/lists"}