May 28th, 2008| 01:00 pm | Posted by vlk
The most widely used tool for detecting sources in X-ray images, especially Chandra data, is the wavelet-based wavdetect, which uses the Mexican Hat (MH) wavelet. Now, the MH is not a very popular choice among wavelet aficianados because it does not form an orthonormal basis set (i.e., scale information is not well separated), and does not have compact support (i.e., the function extends to inifinity). So why is it used here?
Continue reading ‘Mexican Hat [EotW]’ »
Tags:
Chandra,
ciao,
convolution,
correlation,
EotW,
Equation,
Equation of the Week,
Fourier Transform,
gaussian,
MexHat,
Mexican Hat,
MH,
multiscale,
wavdetect,
wavelet Category:
Algorithms,
Astro,
Imaging,
Jargon |
1 Comment
Jan 25th, 2008| 12:53 pm | Posted by hlee
I have been observing some sorts of misconception about statistics and statistical nomenclature evolution in astronomy, which I believe, are attributed to the lack of references in the astronomical society. There are some textbooks designed for junior/senior science and engineering students, which are likely unknown to astronomers. Example-wise, these books are not suitable, to my knowledge. Although I never expect astronomers to learn standard graduate (mathematical) statistics textbooks, I do wish astronomers go beyond Numerical Recipes (W. H. Press, S. A. Teukolsky, W. T. Vetterling, & B. P. Flannery) and Error Data Reduction and Analysis for the Physical Sciences (P. R. Bevington & D. K. Robinson). Here are some good ones written by astronomers, engineers, and statisticians: Continue reading ‘Books - a boring title’ »
Tags:
application,
Bayesian,
books,
box plot,
cartoon,
chi-square,
CLT,
correlation,
delta method,
EDA,
error bars,
Frequentist,
gaussian,
references,
scatter plot Category:
Cross-Cultural,
Misc |
12 Comments