Freeze and thaw matrices

Some terminology: * frozen variables: the variables that have fixed values * warm variables: the remaining variables that vary freely

freeze(input, frozen)

thaw(input, frozen)

Details

A frozen matrix specifies which variables to fix in a projection matrix. Warm variables should be missing (NA) while frozen variables should be set to their fixed values.

Examples

frozen <- matrix(NA, nrow = 4, ncol = 2)
frozen[3, ] <- .5

input <- basis_random(4, 2)
freeze(input, frozen)
#>             [,1]       [,2]
#> [1,] -0.22492742 -0.1346229
#> [2,] -0.32520094  0.3159176
#> [3,]  0.00000000  0.0000000
#> [4,] -0.04685391  0.9306261
thaw(input, frozen)
#>             [,1]       [,2]
#> [1,] -0.19479286 -0.1165868
#> [2,] -0.28163228  0.2735927
#> [3,]  0.50000000  0.5000000
#> [4,] -0.04057667  0.8059458
freeze(basis_random(4, 2), frozen)
#>             [,1]       [,2]
#> [1,]  0.37954586 -0.4266359
#> [2,]  0.91192702  0.2822879
#> [3,]  0.00000000  0.0000000
#> [4,] -0.04077912  0.7419938