# emgr Changelog

## emgr 5.7 (2019-02)

 * CHANGED built-in input argument codes
 * ADDED geometric mean centering
 * ADDED built-in step input
 * ADDED average observability Gramian option
 * IMPROVED exponential chirp input
 * IMPROVED sensitivity Gramian computation
 * IMPROVED linear cross Gramian scales
 * IMPROVED memory footprint of non-symmetric cross Gramians
 * IMPROVED code readability
 * IMPROVED python version
 * REMOVED sensitivity Gramian normalization

## emgr 5.6 (2019-01)

 * ADDED experimental python version
 * ADDED commented custom ends
 * IMPROVED code complexity
 * IMPROVED default integrator
 * IMPROVED parameter perturbations
 * IMPROVED Gramian normalization
 * FIXED bug in linear cross Gramian

## emgr 5.5 (2018-08)

 * ADDED sensitivity Gramian normalization
 * FIXED distributed cross Gramian computation
 * FIXED linear cross Gramian scales
 * FIXED approximate inverse computation
 * FIXED mean centering
 * FIXED parameter centering

## emgr 5.4 (2018-05)

 * CHANGED linear chirp to exponential chirp
 * ADDED input-output sensitivity Gramian
 * ADDED builtin pseudo-random binary input
 * FIXED preconditioner computation

## emgr 5.3 (2018-01)

 * CHANGED preallocation of Gramian variables to reservation
 * CHANGED sequence of computation in linear cross Gramian
 * ADDED local identity function
 * ADDED preallocation for input perturbation
 * FIXED averaging in default integrator

## emgr 5.2 (2017-08)

 * IMPROVED sparse scales
 * FIXED root-mean-square centering
 * REMOVED zero parameter scaling
 * REMOVED wave centering

## emgr 5.1 (2017-05)

 * CHANGED parameter Gramian computation to unified form
 * CHANGED sensitivity Gramian via pseudo kernel
 * ADDED wave centering (experimental)
 * ADDED zero centering
 * ADDED option flags for distributed computation
 * ADDED argument for dot product handle
 * ADDED comment on general Gramian computation
 * IMPROVED preconditioner computation via pseudo kernel
 * IMPROVED handling of extra input
 * IMPROVED partion setup
 * FIXED steady state centering
 * FIXED default integrator
 * REMOVED global variables for distributed computation
 * REMOVED global variable for dot product handle
 * REMOVED argument for parameter scales

## emgr 5.0 (2016-10)

 * CHANGED bsxfun to automatic broadcasting
 * CHANGED output trajectory storage to 3-tensor for cross Gramians
 * CHANGED identifiability Schur complement to approximate inverse
 * CHANGED cross-identifiability Schur complement to approximate inverse
 * CHANGED default integrator to 2nd order SSP RK with enhanced stability
 * ADDED midrange centering
 * ADDED extra input for state Gramians
 * IMPROVED perturbations with sparse vectors
 * FIXED built-in chirp input

## emgr 4.0 (2016-06)

 * CHANGED input scale option order
 * CHANGED state scale option order
 * CHANGED active parameter option
 * CHANGED Gramian pre-allocation
 * CHANGED state and parameter trajectory computations
 * CHANGED centering from lambda to local function
 * CHANGED identifiability Schur complement computation to pseudo inverse
 * CHANGED defualt integrator to 2nd order Heun's method
 * ADDED parameter scales argument pm
 * ADDED inner product handle
 * ADDED distributed cross Gramian computation
 * ADDED distributed cross Gramian configuration
 * ADDED linear non-symmetric cross Gramian
 * ADDED enforced symmetriy for controllability and observability Gramian
 * ADDED zero scales filtering
 * IMPROVED built-in chirp input
 * IMPROVED observability trajectory storage
 * REMOVED robust parameter option
 * REMOVED median centering
 * REMOVED midrange centering
 * REMOVED dyadic rotations
 * REMOVED reciprocal rotations
 * REMOVED sensitivity Gramian centering
 * REMOVED symmetry enforcement option

## emgr 3.9 (2016-02)

 * IMPROVED built-in chirp input
 * FIXED enforce symmetry option

## emgr 3.8 (2015-12)

 * CHANGED parameter Gramian signal
 * CHANGED default parameter centering to none
 * CHANGED parameter sensitivity Gramian is now sparse
 * CHANGED cross-identifiability Schur complement computation to pseudo inverse
 * ADDED active parameter option
 * ADDED enforce symmetry option
 * IMPROVED observability trajectory transformation
 * REMOVED time start from time discretization vector

## emgr 3.6 (2015-10)

 * CHANGED predefined sparse scales
 * ADDED min/max check for parameter Gramians
 * ADDED caching for non-symmetric cross Gramian

## emgr 3.5 (2015-10)

 * CHANGED defualt integrator to Ralston's 2nd order Runge Kutta method
 * ADDED non-symmetric cross Gramian option
 * ADDED logarithmic parameter scale centering
 * FIXED time-series length
 * REMOVED data-driven Gramians option
 * REMOVED symmetrization option (now user responsibility)
 * REMOVED integrator selection option

## emgr 3.1 (2015-05)

 * ADDED midrange centering
 * ADDED root-mean-squared centering
 * ADDED sparse scales
 * IMPROVED default integrators
 * REMOVED pca centering
 * REMOVED pod centering
 * REMOVED trajectory data argument yd

## emgr 3.0 (2015-03)

 * CHANGED constraints for options
 * ADDED gpu hunts
 * IMPROVED performance for observability Gramian product
 * IMPROVED performance for cross Gramian product
 * IMPROVED approximate inverse

## emgr 2.9 (2015-01)

 * CHANGED 3rd accelerated Runge-Kutta to improved 3rd order Runge Kutta solver
 * ADDED zero scales check
 * ADDED non-symmetric cross Gramian (w=x, w=j)
 * ADDED version getter (f='version')
 * REMOVED 1st order Euler integrator
 * REMOVED 2nd order Adams-Bashforth integrator
 * REMOVED 2nd order Ralston integrator
 * REOMVED 2nd order leapfrog integrator

## emgr 2.5 (2014-09)

 * CHANGED centering flag values
 * ADDED optional linear chirp input 
 * ADDED output applicator function
 * ADDED parameter scales

## emgr 2.2 (2014-06)

 * ADDED sensitivity Gramian centering

## emgr 2.1 (2014-05)

 * ADDED zero centering
 * ADDED 3rd order accelerated Runge-Kutta integrator
 * IMPROVED Gramian preallocation

## emgr 2.0 (2014-03)

 * CHANGED config vector order
 * ADDED enforce symmetry option
 * REMOVED rotation configuration

## emgr 1.7 (2014-02)

 * CHANGED Schur complement behavior
 * CHANGED centering and rotations to lambdas
 * ADDED 2nd order Ralston integrator
 * ADDED fast approximate inverse
 * ADDED optional input function as handle
 * ADDED constant parameter excitation
 * FIXED pod centering

## emgr 1.6 (2013-12)

 * CHANGED factorial rotations
 * CHANGED config vector name from cf to nf
 * ADDED empirical linear cross Gramian
 * ADDED custom integrator global handle
 * FIXED normalization

## emgr 1.5 (2013-08)

 * CHANGED parameter argument is now optional
 * REMOVED controllability-observability joint Gramian

## emgr 1.3 (2013-07)

 * CHANGED output trajectory computation
 * CHANGED tabs to spaces
 * CHANGED identifiability Gramian to approximation
 * ADDED Leapfrog Integrator
 * ADDED observability-only joint Gramian
 * ADDED lazy output functional
 * IMPROVED performance for observability Gramian product
 * IMPROVED performance for cross Gramian product
 * REMOVED output integrators

## emgr 1.2 (2013-06)

 * ADDED median centering
 * ADDED 3-tensor storage for observability data
 * IMPROVED performance for observability Gramian product
 * IMPROVED performance for cross Gramian product

## emgr 1.1 (2013-02)

 * ADDED Adams-Bashforth integrator
 * IMPROVED source code comments

## emgr 1.0 (2013-01)

 * CHANGED configuration flags
 * CHANGED pca to pod
 * CHANGED symmetrization behavior
 * ADDED default argument handling
 * ADDED sensitivity Gramian
 * ADDED empirical cross Gramian
 * ADDED empirical joint Gramian
 * ADDED double run option
 * ADDED robust parameter option
 * ADDED sparse option
 * ADDED dirs local function
 * ADDED parfor hints

## emgr 0.9 (2012-10)

 * Initial release for MoRePaS 2