HISTORY.txt

v1.3 (2017-XX-XX)
==================

- Added a fast and precise method for approximating an orbit's
  eccentricity, peri- and apocenter radii, and maximum height above
  the midplane using the Staeckel approximation (see Mackereth & Bovy
  2018); available as an actionAngle method EccZmaxRperiRap and for
  Orbit instances through the e, rperi, rap, and zmax methods.

- Added support for potential wrappers---classes that wrap existing
  potentials to modify their behavior (#307). See the documentation on
  potentials and the potential API for more information on these.

- Added DehnenSmoothWrapperPotential, a potential wrapper to smoothly
  grow a gravitational potential (e.g., a bar) following Dehnen
  (2000).

- Added SolidBodyRotationWrapperPotential, a potential wrapper to make
  a gravitational potential rotate around the z axis with a fixed,
  uniform pattern speed.

- Added DiskSCFPotential, a class that implements general
  density/potential pairs for disk potentials by combining Kuijken &
  Dubinski (1995)'s trick for turning a separable disk density
  [rho(R,z) = \Sigma(R) x h(z)] into a ellipsoidal-ish density, with
  the SCF basis-function-expansion approach of Hernquist & Ostriker
  (1992) for solving for the ellipsoidal-ish density's potential. This
  is a fully general Poisson solver (i.e., any density can be
  represented in this way).

- Added SoftenedNeedleBarPotential, a simple potential for a bar that
  consists of a needle softened by a Miyamoto-Nagai kernel (Long &
  Murali 1992).

- Added FerrersPotential, a class that implements the potential for
  triaxial ellipsoids (Binney & Tremaine 2008, Ch 2.5) with an option
  to give a pattern speed to the ellipsoid.

- Added SpiralArmsPotential, a class that implements the spiral arms
  potential from Cox and Gomez
  (2002). https://arxiv.org/abs/astro-ph/0207635v1 (#305)

- Added the Henon & Heiles (1964) potential

- Added an Orbit method to display an animation of an integrated orbit
  in jupyter notebooks (Orbit.animate).

- Added galpy.df.schwarzschilddf, the simple Schwarzschild
  distribution function for a razor-thin disk.

- Upgraded LogarithmicHaloPotential to allow it to be a triaxial
  potential.

- Upgraded DehnenBarPotential to a 3D potential following Monari et
  al. (2016) (#304).

- Generalized CosmphiDiskPotential to allow for a break radius within
  which the radial dependence of the potential changes from R^p to
  R^-p; also added C implementation of CosmphiDiskPotential.

- Changed default method for computing actions, frequencies, and
  angles for Orbit instances to be the Staeckel approximation with an
  automatically-estimated delta parameter.

- Generalized actionAngleStaeckel to allow for different focal lengths
  delta for different phase-space points. Also allowed the order of
  the Gauss-Legendre integration to be specified (default: 10, which
  is good enough when using actionAngleStaeckel to compute approximate
  actions etc. for an axisymmetric potential).

- Allow transformations of (ra,dec) and (pmra,pmdec) to custom
  coordinate systems.

- Allow plotting of the spherical radius in Orbit.plot

- Allow plotting of arbitrary user-supplied functions of time in
  Orbit.plot, Orbit.plot3d, and Orbit.animate. 

- Added conversion to and from oblate spheroidal coordinates. Also
  added conversion of velocities to the momenta in oblate or prolate
  spheroidal coordinates (but not the other way around).

- Made SCFPotential compatible with GSL v2.

- Orbit methods now all return a scalar when called with a single
  time (see #247 and #294).

- Added a warning whenever the orbit-integration method that is used
  is different from the requested one (for when C integration falls
  back onto Python; see #286).

- Turn off changing the seaborn default plot configuration to that
  preferred by this code's maintainer; can be turned back on by
  specifying ``seaborn-bovy-defaults = True`` in the configuration
  file (see documentation). Old configuration files will be
  automatically updated to add this option (but remain otherwise the
  same).

- Added button to code examples in the documentation that copies the
  examples to the user's clipboard for easy pasting into a Python
  interpreter.

- Switched test suite from nose to pytest (#303).

- quasiisothermaldf.tilt return unit switched from deg to rad.

- streamdf.misalignment return unit switched from deg to rad.

- evolveddiskdf.vertexdev return unit switched from deg to rad.

v1.2 (2016-09-06)
==================

- Added support for providing inputs to all initializations, methods,
  and functions as Quantities with units and for providing outputs as
  astropy Quantities. See pull request #258 and the documentation for
  full details.

- Added TwoPowerTriaxialPotential, a set of triaxial potentials with
  iso-density contours that are arbitrary, similar, coaxial ellipsoids
  whose 'radial' density is a (different) power-law at small and large
  radii: 1/m^alpha/(1+m)^beta-alpha (the triaxial generalization of
  TwoPowerSphericalPotential, with flattening in the density rather
  than in the potential, see Merritt & Fridman 1996, Binney & Tremaine
  2008). These include triaxial Hernquist and NFW potentials. Includes
  fast C implementations that allow efficient orbit integration in
  these potentials (<~5 ms / orbit).

- Added SCFPotential, a class that implements general
  density/potential pairs through the basis expansion approach to
  solving the Poisson equation of Hernquist & Ostriker (1992).  Also
  implemented functions to compute the coefficients for a given
  density function.

- Implemented galpy.actionAngle.actionAngleIsochroneApprox (Bovy 2014)
  for the general case of a time-independent potential, allowing
  action-angle coordinates to be computed for triaxial
  potentials. Previously, this module only supported axisymmetric
  potentials. Also allow the maximum number of terms in the expansion
  to be set object-wide and allow a fixed time-step to be used in the
  necessary orbit integration.

- Added an (experimental) interface to Binney & McMillan's TorusMapper
  code for computing positions and velocities for given actions and
  angles. See the installation instructions for how to properly
  install this.

- Re-defined the amplitude parameters of a few potentials to allow for
  easier setups with amplitudes provided as Quantities with
  units. This is the case for FlattenedPowerPotential,
  PowerSphericalPotential, and PowerSphericalPotentialwCutoff,
  CosmphiDiskPotential, LopsidedDiskPotential, and
  EllipticalDiskPotential.

- Added a module for modeling the effect of a subhalo impact on a
  tidal stream (galpy.df.streamgapdf); see Sanders, Bovy, & Erkal
  (2016). Also includes the fast methods for computing the density
  along the stream and the stream track for a perturbed stream from
  Bovy, Erkal, & Sanders (2016).

- Added functions to galpy.df.streamdf to compute the length of the
  stream, the density along the stream quickly (in various
  coordinates, including custom sky coordinates), to compute the
  probability p(freq_parallel,angle_parallel), and to estimate the
  number of encounters with DM subhalos. Also allow the stream track
  to be computing using the new actionAngleTorus (this last addition
  is still very experimental).

- Added PseudoIsothermalPotential, a standard pseudo-isothermal-sphere
  potential.

- Added KuzminDiskPotential, a potential represented by a razor thin
  disk

- Allow transformations to custom sets of sky coordinates in
  galpy.util.bovy_coords.

- Added the spherical radius as an Orbit method.

- Added the spherical-radial force as a Potential method (rforce) and
  function (evaluaterforces).

- Support for flipping the velocities of an orbit in-place (useful for
  backwards integration).

- quasiisothermaldf input ro replaced by refr to avoid clash with ro
  that specifies units (see above).

- Properly intercept CTRL-C (SIGINT) signals during orbit integration
  in C, allowing long orbit integrations to be interrupted without
  killing an entire Python session.

- Internally use astropy.coordinates transformations to transform
  between (ra,dec) and (l,b). Can be tuned using the astropy-coords
  configuration parameter. Also allow general epochs for the (ra,dec)
  specification.

v1.1 (2015-06-30)
==================

- Added Python 3 support: in particular, Python 3.3 and 3.4 are now
  supported; earlier 3.* may also work, but haven't been
  tested. Python 2 and 3 are supported using a single common codebase.

- Added SnapshotRZPotential and InterpSnapshotRZPotential potential
  classes: these can be used to get a frozen snapshot of the potential
  of an N-body simulation into galpy. SnapshotRZPotential directly
  calculates the potential and forces using direct summation;
  InterpSnapshotRZPotential builds an interpolation table (it's a
  subclass of interpRZPotential and can be used in the same way). This
  code was mainly written by Rok Roskar.

- Added KuzminKutuzovStaeckelPotential, a Staeckel potential that can
  be used to approximate the potential of a disk galaxy (see Batsleer
  & Dejonghe 1994).

- Added MN3ExponentialDiskPotential that gives the approximation to a
  radially-exponential disk potential as three Miyamoto-Nagai disks
  from Smith et al. (2015; arXiv:1502.00627v1)

- Added PlummerPotential, a standard Plummer potential.

- Add support for converting potential parameters to NEMO format and
  units: nemo_accname and nemo_accpars (both instance and general
  Potential method).

- Added nemo/ directory for C++ implementations of additional NEMO
  potentials (not included in the NEMO release); add PowSphwCut.cc for
  PowerSphericalPotential2Cutoff and Makefile to compile and install
  it. This allows gyrfalcON simulations with MWPotential2014.

- Allow user to directly specify the integration step size to use in
  orbit integration.

- Better implementations of vcirc, eipfreq, and verticalfreq for lists
  of potentials that allows for negative amplitude components.

- Improvements to streamdf: add progIsTrack keyword to specify that
  the progenitor= keyword actually specifies the desired starting
  phase-space point of the track; the phase-space point of the
  progenitor is calculated. Refactored streamdf setup to make this
  easy to implement.

- Orbit fitting can now be performed in custom sky coordinates
  (requires one to specify customsky=True and to implement and pass
  the functions (a) lb_to_customsky= and (b) pmllpmbb_to_customsky=,
  similar to lb_to_radec and pmllpmbb_to_pmradec). For example, this
  allows one to do an orbit fit in the GD-1 frame of Koposov et
  al. (2010).

- Orbit.time now returns the times at which an Orbit is integrated if
  called without arguments.

- Slightly improved implementation of actionAngleStaeckel.py (more
  robust umin/umax finding).

v1.0 (2014-12-10)
==================

- Added MWPotential2014: a Milky-Way-like potential fit to a bunch of
  relevant data on the Milky Way; supersedes MWPotential, which is
  still included; changed many examples to use this new potential;

- Changed default integrator to symplec4_c;

- Changed default vo and ro to 220 km/s and 8 kpc, respectively;

- Allow Orbit initialization to specify a distance and velocity scale
  that is then used to output distances, velocities, energies,
  actions, etc. in physical coordinates;

- Added an orbit-fitting routine (Orbit.fit).

- Added virial radius of NFW potential, allow initialization of NFW
  potential with concentration and mass;

- Added potential.mass to return the mass enclosed for individual
  potential instances; both spherical and axisymmetric potentials are
  covered.

- Sped up many of the functions in galpy.util.bovy_coords by removing
  scipy.frompyfunc dependency;

- Added galpy.util.bovy_conversion.dens_in_gevcc,
  galpy.util.bovy_conversion.force_in_10m13kms2,
  galpy.util.bovy_conversion.dens_in_criticaldens,
  galpy.util.bovy_conversion.dens_in_meanmatterdens.

- Much improved test coverage.

- Added planarPotential.LinShuReductionFactor to calculate the
  reduction factor for the response of a kinematically warm population
  to a spiral perturbation.

- Added non-axisymmetric DFs to the top-level and the documentation.

- New streamdf track calculation (see arXiv_v2/published version of
  Bovy 2014); better handdling of coordinate-transformation
  parameters in streamdf.

- Installation now prints informative message about whether or not the
  C extensions were installed.

- More informative warning messages when C functions are not used.

- Fix issues with non-square grids in the C implementation of
  interpRZPotential.

- Added Orbit.flip to generate new Orbit instances with flipped
  velocities.

- Improved actionAngle frequencies for circular orbits.

- Removed actionAngleFlat and actionAnglePower, because they are
  superseded.

- Added hasC_dxdv member to Potential instances to indicate whether or
  not they can be used with integrate_dxdv

- Add C implementation of PowerSphericalPotentialwCutoff;

- Moved MovingObjectPotential, BurkertPotential, and interpRZPotential
  to top level; better implementation of interpRZPotential;

- Better handling of vo,ro, and solarmotion in Orbit instances (Orbit
  initialization value is now used to generate RA, Dec, etc. outputs);

- Added --no-openmp installation option to allow installation without
  OpenMP support (workaround for clang not supporting OpenMP; not
  necessary anymore);


v0.1 (2014-01-09)
==================

- Initial release