excel - Choose a, c, m in Linear Congruential Generator -

-

i looking implement linear congruential generator in excel.

as know, must choose parameter of lcg a, c, m, , z0.

wikipedia says that

the period of general lcg @ m, , choices of factor less that. lcg have full period seed values if , if:

m , offset c relatively prime, - 1 divisible prime factors of m, - 1 divisible 4 if m divisible 4.

also,

 m, 0 < m  – "modulus"  a, 0 < < m – "multiplier"  c, 0 < c < m – "increment"  z0, 0 < z0 < m – "seed" or "start value"

i need choose values, want z0 initial value 10113383, , rest random. nah, values has specified period , guaranteed no collisions duration of period?

i've tried put values, a=13, c=911, m=11584577 , looks no collisions. i'm not sure if break rules or not.

i regularly teach number theory , cryptography course have built library of programs in vba , python. using these, needed write 1 more:

function gcd(num1 long, num2 long) long     dim long     dim b long     = num1     b = num2     dim r long     r = 1     until r = 0         r = mod b         = b         b = r     loop     gcd = end function  sub helper_factor(byval n long, byval p long, factors collection)     'takes passed collection , adds array of form     '(q,k) q >= p smallest prime divisor of n     'p assumed odd     'the function called in such way     'the first divisor found automatically prime      dim q long, k long      q = p     while q <= sqr(n)         if n mod q = 0             k = 1             while n mod q ^ k = 0                 k = k + 1             loop             k = k - 1 'went 1 step far             factors.add array(q, k)             helper_factor n / q ^ k, q + 2, factors             exit sub         end if         q = q + 2     loop     'if here n prime - add factor     factors.add array(n, 1) end sub  function factor(byval n long) collection     dim factors new collection     dim k long      while n mod 2 ^ k = 0         k = k + 1     loop     k = k - 1     if k > 0         n = n / 2 ^ k         factors.add array(2, k)     end if     if n > 1 helper_factor n, 3, factors     set factor = factors end function  function displayfactors(n long) string     dim factors collection     dim long, p long, k long     dim sfactors variant      set factors = factor(n)     redim sfactors(1 factors.count)     = 1 factors.count         p = factors(i)(0)         k = factors(i)(1)         sfactors(i) = p & iif(k > 1, "^" & k, "")     next     displayfactors = join(sfactors, "*") end function  function maxperiod(a long, c long, m long) boolean     'assumes 0 < a,c < m     dim factors collection     dim p long, long      if gcd(c, m) > 1 exit function 'with default value of false     if m mod 4 = 0 , (a - 1) mod 4 > 0 exit function     'else:     set factors = factor(m)     = 1 factors.count         p = factors(i)(0)         if p < m , (a - 1) mod p > 0 exit function     next     'if survive here:     maxperiod = true end function

for example, in intermediate window can check:

?maxperiod(13,911,11584577) true

so seem in luck


Comments

Post a Comment

Popular posts from this blog

java - Run spring boot application error: Cannot instantiate interface org.springframework.context.ApplicationListener -

-
i have spring project , try make use spring boot , run @ embadded tomcat following : https://spring.io/guides/gs/rest-service/ this application //@configuration //@enableaspectjautoproxy @springbootapplication @componentscan(basepackages = "gux.prome") public class application { public static void main(string[] args) { springapplication.run(application.class, args); } } if use maven command: mvn spring-boot:run , project starts fine, need debug , run main method @ intelij, exception occurs: exception in thread "main" java.lang.illegalargumentexception: cannot instantiate interface org.springframework.context.applicationlistener : org.springframework.boot.logging.classpathloggingapplicationlistener @ org.springframework.boot.springapplication.createspringfactoriesinstances(springapplication.java:414) @ org.springframework.boot.springapplication.getspringfactoriesinstances(springapplication.java:394) @ org.springframework.bo...
Read more

reactjs - React router and this.props.children - how to pass state to this.props.children -

-
i'm using react-router first time , don't know how think in yet. here's how i'm loading components in nested routes. entry point .js reactdom.render( <router history={hashhistory} > <route path="/" component={app}> <route path="models" component={content}> </route> </router>, document.getelementbyid('app') ); app.js render: function() { return ( <div> <header /> {this.props.children} </div> ); } so child of app content component sent in. i'm using flux , app.js has state , listens changes, don't know how pass state down this.props.children. before using react-router app.js defines children explicitly, passing state natural don't see how now. using couple of react helper methods can add state, props , whatever else this.props.children render: function() { var children = react.ch...
Read more

Excel VBA "Microsoft Windows Common Controls 6.0 (SP6)" Location Changes -

-
i have excel workbook used generate quotations customers. there main page user inputs data, , there buttons generate various pdfs , send them customer. however, 1 user consistently getting error preventing generating , sending pdfs. i beleive "microsoft windows common controls 6.0 (sp6)". it's installed on users' computers. on mine, location "c:\windows\syswow64\mscomctl.ocx" on others "c:\windows\system32\mscomctl.ocx" the user experiencing issues on 32-bit machine, "mscomctl.ocx" file should in system32. have manually put in there, , pointed common controls reference in vba it. issue seems keep reverting looking in syswow64. since folder doesn't exist, can't find it, , can't produce pdfs. i thought perhaps issue user running older version of office (2007) there users on 2013 , 2016. thought perhaps mixture of 64-bit , 32-bit users. user gets sent workbook other users (as quotation process goes further, gets passed ...
Read more