Re: A program check

*To*: mathgroup at smc.vnet.net*Subject*: [mg75953] Re: A program check*From*: "JGBoone at gmail.com" <JGBoone at gmail.com>*Date*: Mon, 14 May 2007 03:31:42 -0400 (EDT)*References*: <200705030748.DAA17368@smc.vnet.net><f1eqi9$568$1@smc.vnet.net>

On May 4, 12:23 am, anguz... at ing.uchile.cl wrote: > Hello. > I think it's fine, just two comments: > > > speciation:=(hubl[communitysize]=Random[Integer,{size+1,size+100}]); > > (*creates a function that produces a random integer from 11 to 110*) > > Why these numbers? > > > SpeciesCount[lyst_]:= Length[Split[Sort[communitysize]]]; (*counts the > > number groupings of like values there are in communitysize. it does > > this by sorting elements together then Split takes identical elements > > and puts them in sublist then Length counts the sublist*) > > SpeciesCount doesn't use the lyst_ replacement in its definition. I'd > define instead: > > > SpeciesCount[lyst_]:= Length[Split[Sort[lyst]]]; > > Do you see a problem with your implementation? > > Atte. Andres Guzman > > "JGBo... at gmail.com" <JGBo... at gmail.com> ha escrito: > > > > > i was wondering if someone could check this program and see if its > > running like the Description typed under each line says its suppose > > to. > > > ogspecies=10000;(*set up sizes for communitysize and metacommunity*) > > > communitysize= Range[ogspecies];(*makes a vector called communitysize > > with sequencal elements 1 to ogspecies*) > > > metacommunity=Range[ogspecies];(*makes a vector called communitysize > > with sequencal elements 1 to ogspecies*) > > > unlikeliness= 6000;(*sets up chance of speciation.bigger number means > > less likely*) > > > metalikeliness=30; > > (*sets up chance of immigration. bigger number means less likely*) > > > chance:=Random[Integer,{1,unlikeliness}]==1; > > (*creates a function that tests if a random integer from 1 to > > unlikeliness is equal to 1. this makes the chance of speciation equal > > to 1/unlikeliness*) > > > metachance:=Random[Integer,{1,metalikeliness}]\[Equal]1;(*creates a > > function that tests if a random integer from 1 to metalikeliness is > > equal to 1. this makes the chance of speciation equal to 1/ > > metalikeliness*) > > > size:=Length[communitysize];(*gives size a value equal to the number > > of elements in communitysize*) > > > generations=1000000;(*time steps that the funtion runs which is given > > as size squared; this excepted time to monodomince*) > > > hubl[group_]:= group[[Random[Integer,{1,size}]]] ;(*takes a random > > element of group*) > > > metareplace:=(communitysize[[Random[Integer, > > {1,size}]]]=hubl[metacommunity]); > > (*takes random element of community size and replaces it with random > > element of metacommunity by way of the function hubl[group_]*) > > > community:= (communitysize[[Random[Integer, > > {1,size}]]]=hubl[communitysize]); > > (*takes a random element of communitysize and replaces it with another > > random element of community size by way of the function > > hubl[group_]*) > > > speciation:=(hubl[communitysize]=Random[Integer,{size+1,size+100}]); > > (*creates a function that produces a random integer from 11 to 110*) > > > immigration:=If[metachance,metareplace,community]; > > (*asks if metachance is true. if it is true, runs metareplace if not > > it runs community*) > > > changing:=If[chance,speciation,immigration ]; > > > (*makes new vector by replacing random elements of communitysize by > > way of the function speciation if the function chance is true or by > > way of the function immigration if chance is false*) > > > SpeciesCount[lyst_]:= Length[Split[Sort[communitysize]]]; (*counts the > > number groupings of like values there are in communitysize. it does > > this by sorting elements together then Split takes identical elements > > and puts them in sublist then Length counts the sublist*) > > > randomwalks:=Table[changing;{t,SpeciesCount[communitysize]},{t, > > 1,generations}]; > > (*creates a table of the function SpeciesCount from time step 1 till > > generation*) > > > lyst = randomwalks; > > > averagespecies:=N[Mean[Map[Last,lyst]]]; > > (*function produces the mean from SpeciesCount of communitysize over > > the > > total time steps*) > > > halfaveragespecies:=N[Mean[Last/@Take[lyst,{generations/2}]]]; > > (*function produces the mean from SpeciesCount of communitysize over > > half the total time steps*) > > > Print[lyst,{averagespecies}, > > {halfaveragespecies}];ListPlot[lyst,AxesLabel[Rule] > > {"Generations","Number of Species"}] > > > THANKS! > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. i don't quite understand your first question. But i need to rewrite that line anyway. I want it to put in a new number every time its called up. I realize now that there is a possibility for numbers to be put in more than once. the answer to the second question is yes i understand that now. i just learned mathematica this semester and ran this simulation model. so it was really a first attempt at anything serious.

**References**:**A program check***From:*"JGBoone@gmail.com" <JGBoone@gmail.com>