v3.6.0

See CHANGELOG.md.

v3.5.0

Radiation morphs change: diffuse horizontal and direct normal now keep the
EPW's own split, and EPWs without extraterrestrial radiation morph correctly.
Global horizontal radiation and every other variable are unchanged.

Fixed

• No direct normal from EPWs with empty extraterrestrial columns. The
  radiation morph read exthorrad_Whm2 for the clearness index and capped
  direct normal at extdirrad_Whm2. weather-file-builder up to 2.3.0 wrote
  both as 0 in ERA5 typical and extreme years, so every Radiation or Clouds
  and Radiation morph of such a file came out diffuse only, with direct
  normal 0 in every hour. When a column holds no positive value it is now
  computed from the solar position (new procedures.extraterrestrial_or_computed,
  solar.extraterrestrial_radiation) and a warning is logged. The computed
  columns are also written to the morphed EPW (rounded, 0 at night) and named
  in COMMENTS 2. Filled columns are used and written as they are. calc_dirnor also falls back to the solar constant
  when its ceiling column is empty.

Changed

• Diffuse and direct normal keep the EPW's split (procedures.morph_radiation_split).
  Before, both were recalculated from scratch with the Ridley et al. (2010)
  model, which differs from the model the EPW was split with (weather-file-builder
  uses DIRINT). That moved diffuse and direct normal by about 5% even with no
  climate signal (an ERA5 TMY at Zurich: diffuse -5%, direct normal +5%), and
  the error went into every future file. Now the diffuse fraction is the EPW's
  own plus the change the Ridley model predicts between present and morphed
  global radiation, bounded so it never passes the model's future value, and
  direct normal scales the EPW's own value by the change in horizontal beam
  (beam change projected mid-hour where the present beam is under 10 W/m2).
  With no climate signal both are now returned unchanged, and the identity
  tests require it. Zurich ERA5 TMY, CH2025 GWL 3.0 median (global +2.0%):
  diffuse -1.3%, direct normal +4.3% (3.4.0 with the columns filled: -7.7%
  and +10.4%).
• Radiation solar geometry is taken mid-hour. EPW rows are hour-ending
  and the dataframe index marks the start of each hour; the radiation
  procedures took the sun's position at that start, 30 minutes early. They
  now use the middle (solar_geometry(..., offset_minutes=HOUR_MIDPOINT_MINUTES)).
  The returned index and the EPW's date and time columns are unchanged.
• calc_difhor and calc_dirnor remain for a full re-split but the morph no
  longer calls them.

v3.4.0

See CHANGELOG.md.

v3.3.0

See CHANGELOG.md.

v3.2.0

See CHANGELOG.md.

v3.1.0

See CHANGELOG.md.

v3.0.0

This release corrects several morphing calculations. Morphed humidity, dew
point, wind speed, cloud cover, and direct and diffuse radiation all change,
so files produced by earlier versions should be regenerated. Dry bulb
temperature, pressure, and global horizontal radiation are unaffected.

Fixed

• Relative humidity was inflated even with no climate signal. morph_relhum
  evaluated the psychrometer equation at the dry bulb temperature instead of the
  wet bulb temperature, which overstated vapour pressure. Morphing an EPW with an
  unchanged specific humidity raised relative humidity by a median of 21% and
  pushed hundreds of hours to saturation. The conversion now goes through the
  humidity ratio directly and round-trips exactly.
• The humidity climate signal was almost entirely discarded.
  utilities.relative_delta returns a ratio, but morph_relhum treated it as a
  percentage twice over, turning a 20% change in specific humidity into 1%. A
  +20% and a -20% projection produced identical output. The full ratio is now
  applied.
• The wind climate signal was almost entirely discarded. morph_wspd had the
  same ratio-as-percentage bug: a 20% modelled increase in wind speed morphed to
  1.2%.
• Direct normal irradiance could reach physically impossible values.
  calc_dirnor divided the horizontal beam component by the sine of the solar
  altitude with no lower bound, producing values up to 62,000 W/m2 near the
  horizon. Hours below a 2 degree solar altitude are now zeroed and the result is
  capped at the extraterrestrial direct normal irradiance recorded in the EPW.
• Cloud cover changes below 10 percentage points vanished. calc_tsc
  truncated the shift to an integer before applying it, so a 9 percentage point
  change in cloud fraction became zero tenths. The shift is now carried as a float
  and rounded once, at the end.
• Diffuse horizontal irradiance is bounded. The Ridley diffuse fraction is
  clipped to [0, 1] and the result can no longer exceed global horizontal.
• morph_relhum now returns a DatetimeIndex like every other procedure, instead
  of a RangeIndex.
• Appending to the COMMENTS 2 header no longer raises on EPW files that do not
  carry that line; it is created before DATA PERIODS when missing.
• The CMIP6 cache key now includes the time_slices argument, so a custom
  temporal slice no longer silently returns data cut to the default bounds.
• utilities.ts_8760 respects the year argument when a timezone is supplied; it
  previously hard-coded 2022.
• access.build_accessible_data_list returned None; it now returns the list of
  source IDs.

Changed

• Dependencies of a requested variable are now written to the output file.
  Previously, asking for Humidity alone computed a morphed dry bulb temperature
  internally but discarded it, while asking for Dew Point alone wrote it. Every
  resolved dependency is now written, which keeps the morphed EPW internally
  consistent. MorphConfig.resolved_variables exposes the full ordered list.
• Solar geometry uses a fixed UTC offset taken from the EPW LOCATION line
  and the year of the EPW data. It previously looked up a named IANA timezone,
  which injected daylight saving shifts into local solar time that the weather
  data does not contain, and hard-coded three different years.
• procedures.calc_dirnor signature changed. The unused present_dirnor
  argument was removed and extraterrestrial_dirnor and min_solar_altitude
  were added:
  calc_dirnor(morphed_glohor, morphed_difhor, longitude, latitude, utc_offset, extraterrestrial_dirnor=None, min_solar_altitude=2.0)
• procedures.calc_osc returns integer tenths, matching calc_tsc and the EPW
  field definition, instead of floats.
• The CMIP6 cache moved from the system temp directory to the per-user cache
  directory, so it survives a reboot and is not world-readable on shared hosts.
  The default cap rose from 50 MB to 500 MB. PYEPWMORPH_CACHE_DIR and
  PYEPWMORPH_CACHE_MAX_MB override both.
• Cache lookups moved from coordinate.coordinate_cmip6_data into
  workflow.compile_climate_model_data, so a cache hit no longer opens the
  remote catalogue first. Calling coordinate_cmip6_data directly always
  recomputes.
• cache.CACHE_DIR and cache.CACHE_MAX_SIZE_MB were replaced by
  cache.get_cache_dir() and cache.get_cache_max_size_mb(), which read the
  environment on each call.
• The morphing procedures are vectorised. The per-row DataFrame.apply calls
  were replaced with numpy broadcasting, which cuts the radiation chain from
  roughly 1.1 s to a few milliseconds per morph.
• Library modules no longer call warnings.filterwarnings("ignore") at import
  time, which used to silence warnings for the whole host process.
• The cache and utility modules log instead of printing.
• Minimum pandas raised to 2.2, which is the real floor for the "ME" and
  "h" resample aliases already in use.

Removed

• pyepwmorph.tools.ladybug_psychrometrics, which was copied from an
  AGPL-3.0 project into an MIT-licensed package. It is replaced by
  pyepwmorph.tools.psychrometrics, a vectorised implementation of the same
  ASHRAE Handbook (2017) formulas following the MIT-licensed PsychroLib
  reference.
• Unused dependencies: meteocalc, skyfield, ipython, lz4, distributed,
  and timezonefinder.

Added

• pyepwmorph.tools.psychrometrics with vectorised saturation vapour pressure,
  humidity ratio, relative humidity, specific humidity, and dew point functions.
• configuration.resolve_variable_order, which expands variable dependencies
  transitively and returns them in a safe morphing order.
• Epw.add_comment, which appends to COMMENTS 2 and creates the header in the
  correct position when it is absent.
• utilities.month_factors, utilities.day_factors, and utilities.as_array
  for broadcasting monthly and daily climatologies onto an hourly index.
• solar.fixed_offset for building a daylight-saving-free timezone from an EPW
  UTC offset.
• morphing_workflow accepts time_slices and forwards it to the CMIP6 fetch.
• A continuous integration workflow running ruff and the test suite on Python
  3.9 through 3.13.
• The test suite grew from 42 to 104 tests, including an identity-morph suite
  that asserts an unchanged climate leaves the EPW unchanged for every variable.
  That suite alone catches all five numerical bugs fixed in this release.

v2.2.0

What's new

See README for full breaking changes list.

v2.1.1

What's new

See README for full breaking changes list.

v2.1.0

What's new in v2.1.0

See README for full breaking changes list.