QPmat {popbio} | R Documentation |
Build a projection matrix from a time series of individuals (or densities) per stage
Description
Builds one projection matrix from a time series of number (or densities) of individuals per stage (size classes or life stages) using Wood's quadratic programming method. The matrix model also requires a constraint matrix C, vector b, and vector listing nonzero elements of desired projection matrix.
Usage
QPmat(nout, C, b, nonzero)
Arguments
nout |
A time series of population vectors |
C |
constraint matrix |
b |
b vector |
nonzero |
indices of the non-zero elements of the transition matrix (counting by column) |
Details
converted Matlab code from Example 6.3 in Caswell (2001)
Value
A projection matrix.
Note
This function requires solve.QP
in the quadprog
package.
Author(s)
Adapted to R by Patrick Nantel
Examples
## Not run:
## list nonzero elements
nonzero <- c( 1, 2, 5, 6, 7, 9)
## create C matrix
C <- rbind(diag(-1,6), c(1,1,0,0,0,0), c(0,0,1,1,0,0), c(0,0,0,0,0,1))
## calculate b (transpose is not necessary - either way works)
b <- apply(C, 1, max)
QPmat(nematode, C,b,nonzero)
## End(Not run)
[Package popbio version 2.8 Index]