Add changelog for v0.5.0

CHANGELOG.md

@@ -1,6 +1,47 @@
 # Release notes
 
-## [Upcoming release](https://github.com/open2c/cooltools/compare/v0.4.0...HEAD)
+## [Upcoming release](https://github.com/open2c/cooltools/compare/v0.5.0...HEAD)
+
+## [v0.5.0](https://github.com/open2c/cooltools/compare/v0.4.0...v0.5.0)
+
+**NOTE: THIS RELEASE BREAKS BACKWARDS COMPATIBILITY!**
+
+This release addresses two major issues:
+* Integration with bioframe [viewframes](https://bioframe.readthedocs.io/en/latest/guide-intervalops.html#genomic-views) defined as of bioframe v0.3.
+* Synchronization of the CLI and Python API
+
+Additionally, [the documentation](https://cooltools.readthedocs.io/en/latest/) has been greatly improved and now includes detailed tutorials that show how to use the `cooltools` API in conjunction with other Open2C libraries. These tutorials are automatically re-built from notebooks copied from https://github.com/open2c/open2c_examples repository.
+
+### API changes
+* More clear separation of top-level user-facing functions and low-level API.
+  * Most standard analyses can be performed using just the user-facing functions which are imported into the top-level namespace. Some of them are new or heavily modified from earlier versions.
+    * `cooltools.expected_cis` and `cooltools.expected_trans` for average by-diagonal contact frequency in intra-chromosomal data and in inter-chromosomal data, respectively
+    * `cooltools.eigs_cis` and `cooltools.eigs_trans` for eigenvectors (compartment profiles) of cis and trans data, repectively
+    * `cooltools.digitize` and `cooltools.saddle` can be used together for creation of 2D summary tables of Hi-C interactions in relation to a digitized genomic track, such as eigenvectors
+    * `cooltools.insulation` for insulation score and annotation of insulating boundaries
+    * `cooltools.directionality` for directionality index
+    * `cooltools.pileup` for average signal at 1D or 2D genomic features, including APA
+    * `cooltools.coverage` for calculation of per-bin sequencing depth
+    * `cooltools.sample` for random downsampling of cooler files
+
+    * For non-standard analyses that require custom algorithms, a lower level API is available under `cooltools.api`
+
+* Most functions now take an optional `view_df` argument. A pandas dataframe defining a genomic view (https://bioframe.readthedocs.io/en/latest/guide-technical-notes.html) can be provided to limit the analyses to regions included in the view. If not provided, the analysis is performed on whole chromosomes according to what’s stored in the cooler.
+* All functions apart from `coverage` now take a `clr_weight_name` argument to specify how the desired balancing weight column is named. Providing a `None` value allows one to use unbalanced data (except the `eigs_cis`, `eigs_trans` methods, since eigendecomposition is only defined for balanced Hi-C data).
+* The output of `expected-cis` function has changed: it now contains `region1` and `region2` columns (with identical values in case of within-region expected). Additionally, it now allows smoothing of the result to avoid noisy values at long distances (enabled by default and result saved in additional columns of the dataframe)
+* The new `cooltools.insulation` method includes a thresholding step to detect strong boundaries, using either the Li or the Otsu method (from `skimage.thresholding`), or a fixed float value. The result of thresholding for each window size is stored as a boolean in a new column `is_boundary_{window}`.
+* New subpackage `sandbox` for experimental codes that are either candidates for merging into cooltools or candidates for removal. No documentation and tests are expected, proceed at your own risk.
+* New subpackage `lib` for auxiliary modules
+
+### CLI changes
+* CLI tools are renamed with prefixes dropped (e.g. `diamond-insulation` is now `insulation`), to align with names of user-facing API functions.
+* The CLI tool for expected has been split in two for intra- and inter-chromosomal data (`expected-cis` and `expected-trans`, repectively). 
+* Similarly, the compartment profile calculation is now separate for cis and trans (`eigs-cis` and `eigs-trans`).
+* New CLI tool `cooltools pileup` for creation of average features based on Hi-C data. It takes a .bed- or .bedpe-style file to create average on-diagonal or off-diagonal pileups, respectively.
+
+### Maintenance
+Support for Python 3.6 dropped
+
 
 ## [v0.4.0](https://github.com/open2c/cooltools/compare/v0.3.2...v0.4.0)