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From |
"Rubil Ivica" <irubil@eizg.hr> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: RE: RE: A math question |

Date |
Fri, 21 Dec 2012 16:55:58 +0100 |

CJ, both the median and the mean are so-called "functionals" - functions of functions, the latter being (in the case of the mean and the median) the distribution function. In your case, you have a vector-valued function, where the "structure" of the vector is determined by the distribution function of abs(x^3), call it F(.). So what you need is the functional form of F(.). -- Ivica Rubil Ekonomski institut || The Institute of Economics, Zagreb Trg J. F. Kennedyja 7, 10 000 Zagreb, Croatia tel. +385-1-2362-269 || fax. +385-1-2335-165 irubil@eizg.hr || www.eizg.hr -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of CJ Lan Sent: 21. prosinac 2012 16:42 To: statalist@hsphsun2.harvard.edu Subject: st: RE: RE: A math question Al, I think the "median" is a function, just like the "mean" is a function, not just a number. BTW, the derivative of abs(x^3) should be 3*x*abs(x) because the derivative can be derived as abs(x^3)/(x^3)*(3*x^2) = 3*abs(x)*x^2/x = 3*x*abs(x). I wish others could shed a light too? Thx. -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Feiveson, Alan H. (JSC-SK311) Sent: Friday, December 21, 2012 10:28 AM To: statalist@hsphsun2.harvard.edu Subject: st: RE: A math question CJ -The median is one number, not a function - so it doesn't make sense to talk about differentiating it. If you mean what is the derivative of abs(x^3) with respect to x, it would be 3*x^2, because the derivative for x < 0 is the same as for x > 0 = 3*x^2. Al Feiveson -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of CJ Lan Sent: Friday, December 21, 2012 9:13 AM To: statalist@hsphsun2.harvard.edu Subject: st: A math question Folks, I am not sure if this is an appropriate question but I am hoping someone wh= o knows the answer do not mind rendering her/his hands. What is the derivative of the median(abs(x^3)) with respect to x ? Thank you. CJ PLEASE NOTE: Florida has a very broad public records law. Most written communications to or from the Town of Jupiter officials and employees regarding public business are public records available to the public and media upon request. Your e-mail communications may be subject to public disclosure. Under Florida law, e-mail addresses are public records. If you do not want your e-mail address released in response to a public records request, do not send electronic mail to this entity. Instead, contact this office by phone or in writing. The views expressed in this message may not necessarily reflect those of the Town of Jupiter. If you have received this message in error, please notify us immediately by replying to this message, and please delete it from your computer. Thank you. This message has been scanned for malware by Websense. www.websense.com * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**st: on bootstrap***From:*"Rubil Ivica" <irubil@eizg.hr>

**References**:**st: A math question***From:*CJ Lan <CJ@jupiter.fl.us>

**st: RE: A math question***From:*"Feiveson, Alan H. (JSC-SK311)" <alan.h.feiveson@nasa.gov>

**st: RE: RE: A math question***From:*CJ Lan <CJ@jupiter.fl.us>

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