Last chance! 50% off unlimited learning
Sale ends in
firststepatt(A, vector="n", return.N=FALSE)
TRUE
, returns population size in the first time
interval (including effects of asymptotic growth and initial population size),
alongside standardised first-timestep attenuation.vector="n"
, the bound on first-timestep attenuation of A
.
If vector
is specified, the case-specific first-timestep attenuation of the model.
If return.N=TRUE
, a list with components:firststepatt
returns a standardised measure of first-timestep
attenuation, so discounting the effects of both initial population size and asymoptotic
growth (Stott et al. 2011).
If vector
is not specified then the bound on first-timestep attenuation
(the smallest first-timestep attenuation that may be achieved) is returned, otherwise a
case-specific first-timestep attenuation for the specified matrix and demographic structure
is calculated. Note that not all specified demographic structures will yield a
first-timestep attenuation: if the model does not attenuate in the first timestep then an
error is returned and reactivity
should be used.
If return.N=T
then the function also returns realised population size
(including the effects of asymptotic growth and initial population size).
firststepatt
works with imprimitive and irreducible matrices, but returns
a warning in these cases.reactivity
, maxamp
,
maxatt
, inertia
# Create a 3x3 PPM
A <- matrix(c(0,1,2,0.5,0.1,0,0,0.6,0.6), byrow=TRUE, ncol=3)
A
# Create an initial stage structure
initial <- c(3,1,1)
initial
# Calculate the bound on first-timestep attenuation of A
firststepatt(A)
# Calculate case-specific first-timestep attenuation of A
# and initial
firststepatt(A, vector=initial)
# Calculate case-specific first-timestep attenuation of A
# and initial and return realised population size
firststepatt(A, vector=initial, return.N=TRUE)
Run the code above in your browser using DataLab