# Revision history for Persistence
## 1.0 -- 2018-05-11
* First version. Released on an unsuspecting world.
## 1.1 -- 2018-05-27
### Added
- Bottleneck distance, a way to compare the topology of different data sets.
- HasseDiagram module, will allow users to deduce topological features of information flow in networks.
- A function for encoding generic graphs as 2D vectors.
### Changed
- Improved documentation for all exposed modules.
## 1.1.3 -- 2018-07-30
### Changed
- Fixed a major bug with persistent homology; high dimensional holes were being detected in low dimensional data sets.
- Persistent homology now filters out bar codes of the form (i, Just i), as they say nothing about the topology of the underlying complexes.
## 1.1.4 -- 2018-09-15
### Changed
- Fixed spelling error.
- Persistence now exports the constructors for `Extended a`.
## 1.1.4.1 -- 2018-09-15
### Changed
- Fixed all spelling errors, should actually build now.
## 1.1.4.2 -- 2018-09-15
### Changed
- Fixed non-exhaustive pattern match in `BottleNeckDistance` functions.
## 2.0
### Changed
- The module `Persistence` has been renamed to `Filtration,` and all modules now exist within `Persistence`.
- Bar codes now take a type as a parameter so that they can not only represent the filtration indices at which features appear but also the scales.
- Persistent homology functions now take data sets as either vectors or lists.
- Fixed minor issue with bottleneck distance and removed the unsafe functions.
- Improved documentation for all exposed modules
- `Extended` type now exports its constructors.
### Added
- Simplex type synonyms for making other type synonyms and signatures more readable.
- Data structures for filtrations both with and without all vertices having filtration index equal to zero, and persistent homology functions for processing each structure.
- Persistent homology functions that return Bar codes in terms of scales.
- Functions for constructing and manipulating persistence landscapes.
## 2.0.1
### Changed
- Representation of graphs now takes half as much memory.
## 3.0
### Added
- Module for constructing graphs.
- More efficient algorithms for constructing the neighborhood graph.
- Algorithms for dealing with sets of trajectories in Euclidean space.