Displaying 1 result from an estimated 1 matches for "ratio_corr".
2007 Sep 03
0
buglet?? in nlme:::corRatio documentation
...the nugget effect, the
correlation between two observations a distance r apart is
(r/d)^2/(1+(r/d)^2) when no nugget effect is present and
(1-n)*(r/d)^2/(1+(r/d)^2) when a nugget effect is assumed.
This disagrees with the C code (corStruct.c)
/* Rational class */
static double
ratio_corr(double val)
{
double val2 = val * val;
return(1/(1+val2));
}
and with common sense (correlation structures should start from
1 and reach zero for large distances; the structure listed in the
documentation starts at 0 and goes to 1 [or (1-n)] for large distances) --
if you don't want...