two_source_priors_params {trps} | R Documentation |
Adjust Bayesian priors - Two Source Trophic Position
Description
Adjust priors for two source trophic position model derived from Post 2002.
Usage
two_source_priors_params(
a = NULL,
b = NULL,
c1 = NULL,
c1_sigma = NULL,
c2 = NULL,
c2_sigma = NULL,
n1 = NULL,
n1_sigma = NULL,
n2 = NULL,
n2_sigma = NULL,
dn = NULL,
dn_sigma = NULL,
tp_lb = NULL,
tp_ub = NULL,
sigma_lb = NULL,
sigma_ub = NULL,
bp = FALSE
)
Arguments
a |
( |
b |
( |
c1 |
mean ( |
c1_sigma |
variance ( |
c2 |
mean ( |
c2_sigma |
variance ( |
n1 |
mean ( |
n1_sigma |
variance ( |
n2 |
mean ( |
n2_sigma |
variance ( |
dn |
mean ( |
dn_sigma |
variance ( |
tp_lb |
lower bound for priors for trophic position. Defaults to |
tp_ub |
upper bound for priors for trophic position. Defaults to |
sigma_lb |
lower bound for priors for |
sigma_ub |
upper bound for priors for |
bp |
logical value that controls whether informed priors are
supplied to the model for both |
Details
We will use the following equations from Post 2002:
-
\delta^{13}C_c = \alpha * (\delta ^{13}C_1 - \delta ^{13}C_2) + \delta ^{13}C_2
-
\delta^{15}N = \Delta N \times (tp - \lambda_1) + n_1 \times \alpha + n_2 \times (1 - \alpha)
-
\delta^{15}N = \Delta N \times (tp - (\lambda_1 \times \alpha + \lambda_2 \times (1 - \alpha))) + n_1 \times \alpha + n_2 \times (1 - \alpha)
The random exponent (
\alpha
;a
) and shape parameters (\beta
;b
) for\alpha
. This prior assumes a beta distribution.The mean (
c1
;\mu
) and variance (c1_sigma
;\sigma
) of the mean for the first\delta^{13}C
for a given baseline. This prior assumes a normal distributions.The mean (
c2
;\mu
) and variance (c2_sigma
;\sigma
) of the mean for the second\delta^{13}C
for a given baseline. This prior assumes a normal distributions.The mean (
n1
;\mu
) and variance (n1_sigma
;\sigma
) of the mean for the first\delta^{15}N
for a given baseline. This prior assumes a normal distributions.The mean (
n2
;\mu
) and variance (n2_sigma
;\sigma
) of the mean for the second\delta^{15}
N for a given baseline. This prior assumes a normal distributions.The mean (
dn
;\mu
) and variance (dn_sigma
;\sigma
) of\Delta
N (i.e, trophic enrichment factor). This prior assumes a normal distributions.The lower (
tp_lb
) and upper (tp_ub
) bounds for priors for trophic position. This prior assumes a uniform distributions.The lower (
sigma_lb
) and upper (sigma_ub
) bounds for variance (\sigma
). This prior assumes a uniform distributions.
Value
stanvars
object to be used with brms()
call.
See Also
two_source_priors()
, two_source_model()
, and brms::brms()
Examples
two_source_priors_params()