Description Usage Arguments Value Author(s) See Also Examples

Expands a vector of time-varying values into a 2-d matrix for use in MRA model formulas.

1 |

`x` |
The vector of time varying values to expand. This can be
a factor (see |

`nan` |
Number of individuals. Default is to use the 'nan' attribute
of |

`drop.levels` |
A vector of integers specifying which levels of a factor
to drop. Only applicable if |

A 2-d matrix of size `nan`

x `length(x)`

suitable for passing to the
Fortran DLL of MRA for estimation. Values within columns are constant, values
across columns vary according to `x`

. If `x`

is a factor, this matrix
contains 0-1 indicator functions necessary to fit the factor.

If `x`

is a factor, attributes of the returned matrix are
"levels" = levels of the factor and "contr" = contrasts used in the coding (always
`contr.treatment`

). For other contrast coding of factors, make your own
2-d matrix with a call to the appropriate function (like `contr.poly`

).

Trent McDonald, WEST-INC, [email protected]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | ```
nan <- 30
ns <- 5
time.occ <- as.factor(paste("T",1:ns, sep=""))
attr(time.occ,"nan") <- nan
attr(time.occ,"drop.levels") <- ns
time.mat <- tvar(time.occ) # Last occasion is the reference, the SAS and MARK default.
time.mat <- tvar(as.factor(1:ns),nan,ns) #equivalent to above.
# Look at 3-d matrix produced when called with factors
dim(time.mat) <- c(nan,ns,length(levels(time.occ))-1)
print(time.mat) # each page is the 2-d matrix used in the fit.
print(time.mat[1,,])
# compare above to
tvar( 1:ns, nan )
``` |

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