v2.15.0 (14 April 2017)

New Team Members

• Sean Talts (Columbia University) -- Stan and Math libraries
• Imad Ali (Columbia University) -- Bayesian Statistician

Bug Fixes

• Added runtime checks for container variable dimensions (#1194)
• Fixed compiler errors for certain variants of nuts_classic (#2268)
• Fixed compound declaration definition in local blocks (#2145)

New User-Facing Features

• Row-vector and matrix expressions (#1489)
• Better warning message for windowed adaptation (#2064)
• Stan language - model block is optional in a Stan program (#1427)

New Internal Features

• Code cleanup for parser grammars (#2223)
• Exposed new function signatures for to_matrix (#1452)
• Remove initial state from the calculation of the average Metropolis acceptance probability (#2182)
• Refactor stan/lang/generator.hpp (#2204)
• Add informational message to std::domain_error exception (#2203)
• Tweaked windowed adaptation warning to be more readable (#2064)

Documentation

• User manual updates for this release (#2122)