search for: asfr

Dear all i want to estimated the parameter of the gamma density(a,b,d) f(x) = (1/gamma(b)*(a^b)) * ((x-d)^(b-1)) * exp{-(x-d)/a)} for x>d f(x) = Age specific fertility rate x = age when i run this in R by usling nls() gamma.asfr <- formula(asfr ~ (((age-d)^(b-1))/((gamma(b))*(a^b)))* exp(-((age-d)/a))) gamma.asfr1 <- nls(gamma.asfr, data= asfr.aus, start = list(b = 28, a = 1, d= 0.5), trace = TRUE) error: Error in numericDeriv(form[[3L]], names(ind), env) : Missing value or an infinity produced when evaluating the...

Dear all i want to fit the self start model in nls. i have two question. i have a function, (asfr ~ I(((a*b)/c))+ ((c/age)^3/2)+ exp((-b^2)*(c/age)+(age/c)-2) i am wondering how to build the selfstart model. there is lost of example, (i.e. SSgompertz, SSmicman, SSweibull, etc). my question is, how to derive the function of parameters. and also which model to use for get the initials values. In...

Hello Everyone,   Learning about R and its wonderful array of functions. If it's not obvious, I usually try to find out what a function stands for. I think this helps me remember better.   One function that has me stumped is "sink." Can anyone tell me if this stands for something?   Thanks,   Paul         __________________________________________________ [[alternative HTML

...;Rr57&8=<K9X41?GhWEudVOi6Z=Z(8f0q35jQ zkFw^LTIGirqD#&4g3+Bp=<JZkBAZI)3Th<rQSh-ffi2+wV)FL57ce1tPJuUtGXKYq zyL at k}J$gp%NK}W~QQ|(q4Vh&Y5lPK+bm{<;M<eQFpNYBgw~o?5A-#(Q4O(;ILFj5S z^?m9PLl9IG^4@@5W-lZ(yc4Vs$uEjRi_<CTe{SRs&-&w^fByOLqquy(wOe$B at XG4l z(^T3xb!6emiDW_E^ASFr=GnH&V>ZEOT@{a{wLGd5ZyB~WWZ?d~3#aS*peKU@*{O7< zo60CJ-k+p(%Q*?aDWf^1O at cLWXVl&N@$bL?{_lT`UT$+aczEk4d`FsSN0v3jp<;6Q zmZbiWACtJvLLHdnWEORj`Cg#V7o`p_V=LuFhGO_WsELk<x^!L;BA0b3;=Po at pUOS; z>YT$1kRPP3%kE{_KmXnd{m12Y%XeukM|GZpn*5DP^!5|nBe`~NAoRz{iEs+X=Df at v z#=}9gbd#)M+vPHY+b_X^...