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From |
"Michael Blasnik" <michael.blasnik@verizon.net> |

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

Subject |
st: Re: convolution/cumulative |

Date |
Thu, 25 Mar 2004 09:21:02 -0500 |

Just a couple of comments -- You use some strange syntax which appears to be allowed by Stata, but is certainly not standard : gen x = [_n] is usually written: gen x=_n and replace d1 = Sy if [_n] == `i' would be better written: replace d1 = Sy in `i' Also, why do you generate x and x1 within the loop and then drop them at the end of the loop just to recreate again at the top of the loop and finally after the loop? -- they are always the same, aren't they? Michael Blasnik michael.blasnik@verizon.net ----- Original Message ----- From: "Andreas Aschbacher" <aa_surf@gmx.at> To: <statalist@hsphsun2.harvard.edu> Sent: Thursday, March 25, 2004 5:55 AM Subject: st: convolution/cumulative > Dear fellows ! > > maybe the following program is useful for someone: > / computing convolution-integral and cumulative-function / > I seek for possibilities to show that dosis-distributions in population > are composed via convolution of two functions(lognormal ?) > one function represents background - that is radioactivity which is > always around us and not-naturally radioactivity which is for example > radioactivity in a hospital. > physically both allotments are the sum - but !!! probability-distribution in > human-population > is - as we all suppose - composed via convolution.(Bayes-statistic) > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ > clear > set more off > set obs 100 > gen d1 =. > scalar m1 = 3 > scalar m2 = 3.5 > forvalues i = 1(1)100 { > gen x = [_n] > gen x1 = x*.1 > > local j = `i' * .1 > > if `i' == 1 { > local j = .11 > di `j' > } > di `j' > di `j' > > gen double y = exp(-(log((`j') - x1) - m1 )^2/2) *exp(-(log((`j') - x1) - > m2)^2/2) > /standard-deviation = 1 for both / > replace y = 0 if x1 > `j' > di `j' > integ y x1 ,gen(Sy) > replace d1 = Sy if [_n] == `i' > drop Sy y x x1 > } > gen x = [_n] > gen x1 = x*.1 > > integ d1 x1,gen(Sy_1) > twoway line d1 x1||line Sy_1 x1 > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > greetings from austria > andreas aschbacher * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Re: convolution/cumulative***From:*"Andreas Aschbacher" <aa_surf@gmx.at>

**References**:**st: convolution/cumulative***From:*"Andreas Aschbacher" <aa_surf@gmx.at>

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