Jun 1st, 2009| 09:51 pm | Posted by hlee

How would you assign orders to multivariate data? If you have your strategy to achieve this ordering task, I’d like to ask, “is your strategy **affine invariant**?” meaning that shift and rotation invariant. Continue reading ‘[MADS] data depth’ »

Tags:

break points,

data depth,

MADS,

mean,

median,

multivariate,

nonparametric,

order,

parasite,

quantile,

robust,

sort,

vertebrate Category:

Algorithms,

arXiv,

Cross-Cultural,

Jargon,

Stat |

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May 18th, 2009| 12:18 pm | Posted by hlee

My understandings of **“robustness”** from the education in statistics and from communicating with astronomers are hard to find a mutual interest. Can anyone help me to build a robust bridge to get over this abyss? Continue reading ‘Robust Statistics’ »

Tags:

break point,

Huber,

nonparametric,

robust,

Rousseeuw,

Tukey Category:

Bayesian,

Frequentist,

Jargon,

MCMC,

Methods,

Quotes,

Stat,

Uncertainty |

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Dec 10th, 2008| 01:41 pm | Posted by hlee

We have seen the word “bipartisan” often during the election and during the on-going recession period. Sometimes, I think that the bipartisanship is not driven by politicians but it’s driven by media, commentator, and interpreters. Continue reading ‘Bipartisanship’ »

Tags:

bipartisan,

Joe Liberman,

robust,

robust statistics Category:

Astro,

Bayesian,

Frequentist,

Galaxies,

Misc,

Quotes,

Stat,

Timing |

2 Comments
May 5th, 2008| 03:08 am | Posted by hlee

Since I learned Hubble’s tuning fork^{[1]} for the first time, I wanted to do classification (semi-supervised learning seems more suitable) galaxies based on their features (colors and spectra), instead of labor intensive human eye classification. Ironically, at that time I didn’t know there is a field of computer science called machine learning nor statistics which do such studies. Upon switching to statistics with a hope of understanding statistical packages implemented in IRAF and IDL, and learning better the contents of Numerical Recipes and Bevington’s book, the ignorance was not the enemy, but the accessibility of data was. Continue reading ‘[ArXiv] 5th week, Apr. 2008’ »

Tags:

ANN,

automation,

Classification,

correlation function,

denoising,

FFT,

gravitational wave,

lensing,

LISA,

machine learning,

missing data,

mock data,

morphology,

PCA,

power spectrum,

robust,

SDSS,

spectrum,

sunspots,

wavelet,

zoo Category:

arXiv,

Galaxies,

Imaging,

MCMC,

Physics,

Spectral |

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Oct 30th, 2007| 03:37 am | Posted by hlee

From arxiv/astro-ph:0705.4199v1

**In search of an unbiased temperature estimator for statistically poor X-ray spectra**

A. Leccardi and S. Molendi

There was a delay of writing about this paper, which by accident was lying under the pile of papers irrelevant to astrostatistics. (It has been quite overwhelming to track papers with various statistical applications and papers with rooms left for statistical improvements from arxiv:astro-ph). Although there is a posting about this paper (see Vinay’s posting), I’d like to give a shot. I was very excited because I haven’t seen any astronomical papers discussing **unbiased estimators** solely.

Continue reading ‘[ArXiv] An unbiased estimator, May 29, 2007’ »

Tags:

chi-square,

maximum likelihood,

mixing distribution,

mixture,

nonparametric,

robust,

subsampling,

transformation,

unbiased,

Uncertainty Category:

arXiv,

Frequentist,

Stat |

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