Date: 2018-11-12

Reading Varying Iteration Padding Reading

Support reading series with varying iteration padding (or no padding at all) as currently used in PIConGPU.

Changes to “0.6.2-alpha”

Bug Fixes

  • support reading series with varying or no iteration padding in filename #388


Date: 2018-09-25

Python Stride: Regression

A regression in the last fix for python strides made the relaxation not efficient for 2-D and higher.

Changes to “0.6.1-alpha”

Bug Fixes

  • Python: relax strides further


Date: 2018-09-24

Relaxed Python Stride Checks

Python stride checks have been relaxed and one-element n-d arrays are allowed for scalars.

Changes to “0.6.0-alpha”

Bug Fixes

  • Python:
    • stride check too strict #369
    • allow one-element n-d arrays for scalars in store, make_constant #314


  • dependency change: Catch2 2.3.0+
  • Python: add extended write example #314


Date: 2018-09-20

Particle Patches Improved, Constant Scalars and Python Containers Fixed

Scalar records properly support const-ness. The Particle Patch load interface was changed, loading now all patches at once, and Python bindings are available. Numpy dtype is now a first-class citizen for Python Datatype control, being accepted and returned instead of enums. Python lifetime in garbage collection for containers such as meshes, particles and iterations is now properly implemented.

Changes to “0.5.0-alpha”


  • Python:
    • accept & return numpy.dtype for Datatype #351
    • better check for (unsupported) numpy array strides #353
    • implement Record_Component.make_constant #354
    • implement Particle_Patches #362
  • comply with runtime constraints w.r.t. written status #352
  • load at once ParticlePatches.load() #364

Bug Fixes

  • dataOrder: mesh attribute is a string #355
  • constant scalar Mesh Records: reading corrected #358
  • particle patches: stricter load( idx ) range check #363, then removed in #364
  • Python: lifetime of Iteration.meshes/particles and Series.iterations members #354


  • test cases for mixed constant/non-constant Records #358
  • examples: close handles explicitly #359 #360


Date: 2018-09-17

Refactored Type System

The type system for Datatype::``s was refactored. Integer types are now represented by ``SHORT, INT, LONG and LONGLONG as fundamental C/C++ types. Python support enters “alpha” stage with fixed floating point storage and Attribute handling.

Changes to “0.4.0-alpha”


  • Removed Datatype::INT32 types with ::SHORT, ::INT equivalents #337
  • Attribute::get<...>() performs a static_cast now #345

Bug Fixes

  • Refactor type system and Attribute set/get
    • integers #337
    • support long double reads on MSVC #184
  • setAttribute: explicit C-string handling #341
  • Dataset: setCompression warning and error logic #326
  • avoid impact on unrelated classes in invasive tests #324
  • Python
    • single precision support: numpy.float is an alias for builtins.float #318 #320
    • Dataset method namings to underscores #319
    • container namespace ambiguity #343
    • set_attribute: broken numpy, list and string support #330


  • CMake: invasive tests not enabled by default #323
  • store_chunk: more detailed type mismatch error #322
  • no_such_file_error & no_such_attribute_error: remove c-string constructor #325 #327
  • add virtual destructor to Attributable #332
  • Python: Numpy 1.15+ required #330


Date: 2018-08-27

Improved output handling

Refactored and hardened for fileBased output. Records are not flushed before the ambiguity between scalar and vector records are resolved. Trying to write globally zero-extent records will throw gracefully instead of leading to undefined behavior in backends.

Changes to “0.3.1-alpha”


  • do not assume record structure prematurely #297
  • throw in (global) zero-extent dataset creation and write #309

Bug Fixes

  • ADIOS1 fileBased IO #297
  • ADIOS2 stub header #302
  • name sanitization in ADIOS1 and HDF5 backends #310


  • CI updates: #291
    • measure C++ unit test coverage with coveralls
    • clang-format support
    • clang-tidy support
    • include-what-you-use support #291 export headers #300
    • OSX High Sierra support #301
    • individual cache per build # 303
    • readable build names #308
  • remove superfluous whitespaces #292
  • readme: openPMD is for scientific data #294
  • override implies virtual #293
  • spack load: -r #298
  • default constructors and destructors #304
  • string pass-by-value #305
  • test cases with 0-sized reads & writes #135


Date: 2018-07-07

Refined fileBased Series & Python Data Load

A specification for iteration padding in filenames for fileBased series is introduced. Padding present in read iterations is detected and conserved in processing. Python builds have been simplified and python data loads now work for both meshes and particles.

Changes to “0.3.0-alpha”


  • CMake:
    • add openPMD::openPMD alias for full-source inclusion #277
    • include internally shipped pybind11 v2.2.3 #281
    • ADIOS1: enable serial API usage even if MPI is present #252 #254
  • introduce detection and specification %0\d+T of iteration padding #270
  • Python:
    • add unit tests #249
    • expose record components for particles #284

Bug Fixes

  • improved handling of fileBased Series and READ_WRITE access
  • expose Container constructor as protected rather than public #282
  • Python:
    • return actual data in load_chunk #286


  • docs:
    • improve “Install from source” section #274 #285
    • Spack python 3 install command #278


Date: 2018-06-18

Python Attributes, Better FS Handling and Runtime Checks

This release exposes openPMD attributes to Python. A new independent mechanism for verifying internal conditions is now in place. Filesystem support is now more robust on varying directory separators.

Changes to “0.2.0-alpha”


  • CMake: add new openPMD_USE_VERIFY option #229
  • introduce VERIFY macro for pre-/post-conditions that replaces ASSERT #229 #260
  • serial Singularity container #236
  • Python:
    • expose attributes #256 #266
    • use lists for offsets & extents #266
  • C++:
    • setAttribute signature changed to const ref #268

Bug Fixes

  • handle directory separators platform-dependent #229
  • recursive directory creation with existing base #261
  • FindADIOS.cmake: reset on multiple calls #263
  • SerialIOTest: remove variable shadowing #262
  • ADIOS1: memory violation in string attribute writes #269


  • enforce platform-specific directory separators on user input #229
  • docs:
    • link updates to https #259
    • minimum MPI version #251
    • title updated #235
  • remove MPI from serial ADIOS interface #258
  • better name for scalar record in examples #257
  • check validity of internally used pointers #247
  • various CI updates #246 #250 #261


Date: 2018-06-11

Initial Numpy Bindings

Adds first bindings for record component reading and writing. Fixes some minor CMake issues.

Changes to “0.1.1-alpha”


  • Python: first NumPy bindings for record component chunk store/load #219
  • CMake: add new BUILD_EXAMPLES option #238
  • CMake: build directories controllable #241

Bug Fixes

  • forgot to bump version.hpp/__version__ in last release
  • CMake: Overwritable Install Paths #237


Date: 2018-06-07

ADIOS1 Build Fixes & Less Flushes

We fixed build issues with the ADIOS1 backend. The number of performed flushes in backends was generally minimized.

Changes to “0.1.0-alpha”

Bug Fixes

  • SerialIOTest: loadChunk template missing for ADIOS1 #227
  • prepare running serial applications linked against parallel ADIOS1 library #228


  • minimize number of flushes in backend #212


Date: 2018-06-06

This is the first developer release of openPMD-api.

Both HDF5 and ADIOS1 are implemented as backends with serial and parallel I/O support. The C++11 API is considered alpha state with few changes expected to come. We also ship an unstable preview of the Python3 API.