flexit {HelpersMG} | R Documentation |
Return the flexit
Description
Return a vector with the probabilities.
The flexit equation is published in:
Abreu-Grobois, F.A., Morales-Mérida, B.A., Hart, C.E., Guillon, J.-M., Godfrey, M.H.,
Navarro, E. & Girondot, M. (2020) Recent advances on the estimation of the thermal
reaction norm for sex ratios. PeerJ, 8, e8451.
If dose < P then (1+(2K1−1)∗exp(4∗S1∗(P−x)))(−1/K1)
If dose > P then 1−((1+(2K2−1)∗exp(4∗S2∗(x−P)))(−1/K2)
with:
S1=(2(K1−1)∗S∗K1)/(2K1−1)
S2=(2(K2−1)∗S∗K2)/(2K2−1)
New in version 4.7-3 and larger:
If 2K1
is too large to be estimated, the approximation S1=S∗K1/2
is used.
Demonstration:
S1=(2(K1−1)∗S∗K1)/(2K1−1)
S1=exp(log((2(K1−1)∗S∗K1)/(2K1−1)))
S1=exp(log(2(K1−1))+log(S∗K1)−log(2K1−1))
When K1
is very large, 2K1−1=2K1
then
S1=exp((K1−1)∗log(2)+log(S∗K1)−K1∗log(2))
S1=exp((K1∗log(2)−log(2)+log(S∗K1)−K1∗log(2))
S1=exp(log(S∗K1)−log(2))
S1=S∗K1/2
If 2K2
is too large to be estimated, the approximation S2=S∗K2/2
is used.
If (1+(2K1−1)∗exp(4∗S1∗(P−x)))(−1/K1)
is not finite,
the following approximation is used:
exp((−1/K1)∗(K1∗log(2)+(4∗S1∗(P−x))))
If 1−((1+(2K2−1)∗exp(4∗S2∗(x−P)))(−1/K2)
is not finite,
the following approximation is used:
1−exp((−1/K2)∗(K2∗log(2)+(4∗S2∗(x−P))))
Usage
flexit(
x,
par = NULL,
P = NULL,
S = NULL,
K1 = NULL,
K2 = NULL,
zero = 1e-09,
error0 = 0,
error1 = 1
)
Arguments
x |
The values at which the flexit model must be calculated
|
par |
The vector with P, S, K1, and K2 values
|
P |
P value
|
S |
S value
|
K1 |
K1 value
|
K2 |
K2 value
|
zero |
Value to replace zero
|
error0 |
Value to return if an error is observed toward 0
|
error1 |
Value to return if an error is observed toward 1
|
Details
Return the flexit value
Value
A vector with the probabilities
Author(s)
Marc Girondot marc.girondot@gmail.com
See Also
Other logit:
invlogit()
,
logit()
Examples
n <- flexit(x=1:100, par=c(P=50, S=0.001, K1=0.01, K2=0.02))
n <- flexit(x=1:100, P=50, S=0.001, K1=0.01, K2=0.02)
1/(1+exp(0.01*4*(50-1:100)))
flexit(1:100, P=50, S=0.01, K1=1, K2=1)
[Package
HelpersMG version 6.1
Index]