da {jumps} | R Documentation |
Internal function for computing scores w/r to regression coefficients
Description
This function, not intended for end-users, implements the following recursions needed in computing scores with respect to regression coefficients:
D a^{(1)}_{t+1} = D a^{(1)}_{t} + D a^{(2)}_{t} - k^{(1)}_t x_t -
k^{(1)}_t D a^{(1)}_{t}
D a^{(2)}_{t+1} = a^{(2)}_{t} - k^{(2)}_t x_t - k^{(2)}_t Da^{(1)}_{t}
where a^{(1)}_{t}
, a^{(2)}_{t}
are the one-step-ahead Kalman filtered
state variables, and k^{(1)}_{t}
, k^{(2)}_{t}
the respective
Kalman gain elements. The symbol $D$ represent the partial derivative with
respect to the regression coefficients and $x_t$ is the vector of regressors.
All variables are passed by reference and, so, no output is needed.
Usage
da(k1, k2, X, A1, A2)
Arguments
k1 |
numeric vector of n elements with the Kalman gain sequence for the first state variable; |
k2 |
numeric vector of n elements with the Kalman gain sequence for the second state variable; |
X |
numeric matrix of dimension |
A1 |
numeric matrix of dimension |
A2 |
numeric matrix of dimension |
Value
It does not return anything as it writes on the A1 and A2 matrices passed as reference.