A sample of rotational velocities of stars from Hoffleit and
Warren (1991) similar to that previosly considered by Pal, Woodroofe and Meyer (2007)
and used by Koenker and Mizera (2010). The demo(velo)
illustrates fitted
densities for three relatively weak concavity constraints corresponding to
\(-1/sqrt(f)\), \(-1/f\) and \(-1/f^2\) constrained to be concave.
Note that last of these pushes the optimization methods about as far as they can do.
velo
A numeric vector with 3933 observations on one variable.
velo
a numeric vector with rotational velocities.
Pal, J. K., Woodroofe, M. and Meyer, M. (2007). Estimating a Polya frequency function. In Complex Datasets and Inverse Problems: Tomography, Networks and Beyond, (R. Liu, W. Strawderman, and C.-H. Zhang, eds.). IMS Lecture Notes-Monograph Series 54 239-249. Institute of Mathematical Statistics. Koenker, R. and Mizera, I. (2010) Quasi-Concave Density Estimation, Annals of Statistics, 38, 2998-3027.