Extract the variance-covariance matrix from a fitted model, such as a mixed-effects model.

getVarCov(obj, ...)
# S3 method for class 'lme'
getVarCov(obj, individuals,
    type = c("random.effects", "conditional", "marginal"), ...)
# S3 method for class 'gls'
getVarCov(obj, individual = 1, ...)

Arguments

obj

A fitted model. Methods are available for models fit by lme and by gls

individuals

For models fit by lme a vector of levels of the grouping factor can be specified for the conditional or marginal variance-covariance matrices.

individual

For models fit by gls the only type of variance-covariance matrix provided is the marginal variance-covariance of the responses by group. The optional argument individual specifies the group of responses.

type

For models fit by lme the type argument specifies the type of variance-covariance matrix, either "random.effects" for the random-effects variance-covariance (the default), or "conditional" for the conditional. variance-covariance of the responses or "marginal" for the the marginal variance-covariance of the responses.

...

Optional arguments for some methods, as described above

Value

A variance-covariance matrix or a list of variance-covariance matrices.

Author

Mary Lindstrom lindstro@biostat.wisc.edu

See also

Examples

fm1 <- lme(distance ~ age, data = Orthodont, subset = Sex == "Female")
getVarCov(fm1)
#> Random effects variance covariance matrix
#>             (Intercept)       age
#> (Intercept)     3.55020 -0.107490
#> age            -0.10749  0.025898
#>   Standard Deviations: 1.8842 0.16093 
getVarCov(fm1, individuals = "F01", type = "marginal")
#> Subject F01 
#> Marginal variance covariance matrix
#>        1      2      3      4
#> 1 3.9344 3.6872 3.8866 4.0860
#> 2 3.6872 4.4368 4.2931 4.5961
#> 3 3.8866 4.2931 5.1463 5.1063
#> 4 4.0860 4.5961 5.1063 6.0630
#>   Standard Deviations: 1.9835 2.1064 2.2685 2.4623 
getVarCov(fm1, type = "conditional")
#> Subject F01 
#> Conditional variance covariance matrix
#>         1       2       3       4
#> 1 0.44659 0.00000 0.00000 0.00000
#> 2 0.00000 0.44659 0.00000 0.00000
#> 3 0.00000 0.00000 0.44659 0.00000
#> 4 0.00000 0.00000 0.00000 0.44659
#>   Standard Deviations: 0.66827 0.66827 0.66827 0.66827 
fm2 <- gls(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), Ovary,
           correlation = corAR1(form = ~ 1 | Mare))
getVarCov(fm2)
#> Marginal variance covariance matrix
#>             [,1]      [,2]      [,3]      [,4]      [,5]      [,6]      [,7]
#>  [1,] 21.3090000 16.050000 12.089000  9.105600  6.858400  5.165800  3.890900
#>  [2,] 16.0500000 21.309000 16.050000 12.089000  9.105600  6.858400  5.165800
#>  [3,] 12.0890000 16.050000 21.309000 16.050000 12.089000  9.105600  6.858400
#>  [4,]  9.1056000 12.089000 16.050000 21.309000 16.050000 12.089000  9.105600
#>  [5,]  6.8584000  9.105600 12.089000 16.050000 21.309000 16.050000 12.089000
#>  [6,]  5.1658000  6.858400  9.105600 12.089000 16.050000 21.309000 16.050000
#>  [7,]  3.8909000  5.165800  6.858400  9.105600 12.089000 16.050000 21.309000
#>  [8,]  2.9307000  3.890900  5.165800  6.858400  9.105600 12.089000 16.050000
#>  [9,]  2.2074000  2.930700  3.890900  5.165800  6.858400  9.105600 12.089000
#> [10,]  1.6626000  2.207400  2.930700  3.890900  5.165800  6.858400  9.105600
#> [11,]  1.2523000  1.662600  2.207400  2.930700  3.890900  5.165800  6.858400
#> [12,]  0.9432500  1.252300  1.662600  2.207400  2.930700  3.890900  5.165800
#> [13,]  0.7104600  0.943250  1.252300  1.662600  2.207400  2.930700  3.890900
#> [14,]  0.5351300  0.710460  0.943250  1.252300  1.662600  2.207400  2.930700
#> [15,]  0.4030600  0.535130  0.710460  0.943250  1.252300  1.662600  2.207400
#> [16,]  0.3035900  0.403060  0.535130  0.710460  0.943250  1.252300  1.662600
#> [17,]  0.2286700  0.303590  0.403060  0.535130  0.710460  0.943250  1.252300
#> [18,]  0.1722300  0.228670  0.303590  0.403060  0.535130  0.710460  0.943250
#> [19,]  0.1297300  0.172230  0.228670  0.303590  0.403060  0.535130  0.710460
#> [20,]  0.0977120  0.129730  0.172230  0.228670  0.303590  0.403060  0.535130
#> [21,]  0.0735970  0.097712  0.129730  0.172230  0.228670  0.303590  0.403060
#> [22,]  0.0554340  0.073597  0.097712  0.129730  0.172230  0.228670  0.303590
#> [23,]  0.0417530  0.055434  0.073597  0.097712  0.129730  0.172230  0.228670
#> [24,]  0.0314490  0.041753  0.055434  0.073597  0.097712  0.129730  0.172230
#> [25,]  0.0236880  0.031449  0.041753  0.055434  0.073597  0.097712  0.129730
#> [26,]  0.0178420  0.023688  0.031449  0.041753  0.055434  0.073597  0.097712
#> [27,]  0.0134380  0.017842  0.023688  0.031449  0.041753  0.055434  0.073597
#> [28,]  0.0101220  0.013438  0.017842  0.023688  0.031449  0.041753  0.055434
#> [29,]  0.0076239  0.010122  0.013438  0.017842  0.023688  0.031449  0.041753
#>            [,8]      [,9]     [,10]    [,11]    [,12]    [,13]    [,14]
#>  [1,]  2.930700  2.207400  1.662600  1.25230  0.94325  0.71046  0.53513
#>  [2,]  3.890900  2.930700  2.207400  1.66260  1.25230  0.94325  0.71046
#>  [3,]  5.165800  3.890900  2.930700  2.20740  1.66260  1.25230  0.94325
#>  [4,]  6.858400  5.165800  3.890900  2.93070  2.20740  1.66260  1.25230
#>  [5,]  9.105600  6.858400  5.165800  3.89090  2.93070  2.20740  1.66260
#>  [6,] 12.089000  9.105600  6.858400  5.16580  3.89090  2.93070  2.20740
#>  [7,] 16.050000 12.089000  9.105600  6.85840  5.16580  3.89090  2.93070
#>  [8,] 21.309000 16.050000 12.089000  9.10560  6.85840  5.16580  3.89090
#>  [9,] 16.050000 21.309000 16.050000 12.08900  9.10560  6.85840  5.16580
#> [10,] 12.089000 16.050000 21.309000 16.05000 12.08900  9.10560  6.85840
#> [11,]  9.105600 12.089000 16.050000 21.30900 16.05000 12.08900  9.10560
#> [12,]  6.858400  9.105600 12.089000 16.05000 21.30900 16.05000 12.08900
#> [13,]  5.165800  6.858400  9.105600 12.08900 16.05000 21.30900 16.05000
#> [14,]  3.890900  5.165800  6.858400  9.10560 12.08900 16.05000 21.30900
#> [15,]  2.930700  3.890900  5.165800  6.85840  9.10560 12.08900 16.05000
#> [16,]  2.207400  2.930700  3.890900  5.16580  6.85840  9.10560 12.08900
#> [17,]  1.662600  2.207400  2.930700  3.89090  5.16580  6.85840  9.10560
#> [18,]  1.252300  1.662600  2.207400  2.93070  3.89090  5.16580  6.85840
#> [19,]  0.943250  1.252300  1.662600  2.20740  2.93070  3.89090  5.16580
#> [20,]  0.710460  0.943250  1.252300  1.66260  2.20740  2.93070  3.89090
#> [21,]  0.535130  0.710460  0.943250  1.25230  1.66260  2.20740  2.93070
#> [22,]  0.403060  0.535130  0.710460  0.94325  1.25230  1.66260  2.20740
#> [23,]  0.303590  0.403060  0.535130  0.71046  0.94325  1.25230  1.66260
#> [24,]  0.228670  0.303590  0.403060  0.53513  0.71046  0.94325  1.25230
#> [25,]  0.172230  0.228670  0.303590  0.40306  0.53513  0.71046  0.94325
#> [26,]  0.129730  0.172230  0.228670  0.30359  0.40306  0.53513  0.71046
#> [27,]  0.097712  0.129730  0.172230  0.22867  0.30359  0.40306  0.53513
#> [28,]  0.073597  0.097712  0.129730  0.17223  0.22867  0.30359  0.40306
#> [29,]  0.055434  0.073597  0.097712  0.12973  0.17223  0.22867  0.30359
#>          [,15]    [,16]    [,17]    [,18]    [,19]     [,20]     [,21]
#>  [1,]  0.40306  0.30359  0.22867  0.17223  0.12973  0.097712  0.073597
#>  [2,]  0.53513  0.40306  0.30359  0.22867  0.17223  0.129730  0.097712
#>  [3,]  0.71046  0.53513  0.40306  0.30359  0.22867  0.172230  0.129730
#>  [4,]  0.94325  0.71046  0.53513  0.40306  0.30359  0.228670  0.172230
#>  [5,]  1.25230  0.94325  0.71046  0.53513  0.40306  0.303590  0.228670
#>  [6,]  1.66260  1.25230  0.94325  0.71046  0.53513  0.403060  0.303590
#>  [7,]  2.20740  1.66260  1.25230  0.94325  0.71046  0.535130  0.403060
#>  [8,]  2.93070  2.20740  1.66260  1.25230  0.94325  0.710460  0.535130
#>  [9,]  3.89090  2.93070  2.20740  1.66260  1.25230  0.943250  0.710460
#> [10,]  5.16580  3.89090  2.93070  2.20740  1.66260  1.252300  0.943250
#> [11,]  6.85840  5.16580  3.89090  2.93070  2.20740  1.662600  1.252300
#> [12,]  9.10560  6.85840  5.16580  3.89090  2.93070  2.207400  1.662600
#> [13,] 12.08900  9.10560  6.85840  5.16580  3.89090  2.930700  2.207400
#> [14,] 16.05000 12.08900  9.10560  6.85840  5.16580  3.890900  2.930700
#> [15,] 21.30900 16.05000 12.08900  9.10560  6.85840  5.165800  3.890900
#> [16,] 16.05000 21.30900 16.05000 12.08900  9.10560  6.858400  5.165800
#> [17,] 12.08900 16.05000 21.30900 16.05000 12.08900  9.105600  6.858400
#> [18,]  9.10560 12.08900 16.05000 21.30900 16.05000 12.089000  9.105600
#> [19,]  6.85840  9.10560 12.08900 16.05000 21.30900 16.050000 12.089000
#> [20,]  5.16580  6.85840  9.10560 12.08900 16.05000 21.309000 16.050000
#> [21,]  3.89090  5.16580  6.85840  9.10560 12.08900 16.050000 21.309000
#> [22,]  2.93070  3.89090  5.16580  6.85840  9.10560 12.089000 16.050000
#> [23,]  2.20740  2.93070  3.89090  5.16580  6.85840  9.105600 12.089000
#> [24,]  1.66260  2.20740  2.93070  3.89090  5.16580  6.858400  9.105600
#> [25,]  1.25230  1.66260  2.20740  2.93070  3.89090  5.165800  6.858400
#> [26,]  0.94325  1.25230  1.66260  2.20740  2.93070  3.890900  5.165800
#> [27,]  0.71046  0.94325  1.25230  1.66260  2.20740  2.930700  3.890900
#> [28,]  0.53513  0.71046  0.94325  1.25230  1.66260  2.207400  2.930700
#> [29,]  0.40306  0.53513  0.71046  0.94325  1.25230  1.662600  2.207400
#>           [,22]     [,23]     [,24]     [,25]     [,26]     [,27]     [,28]
#>  [1,]  0.055434  0.041753  0.031449  0.023688  0.017842  0.013438  0.010122
#>  [2,]  0.073597  0.055434  0.041753  0.031449  0.023688  0.017842  0.013438
#>  [3,]  0.097712  0.073597  0.055434  0.041753  0.031449  0.023688  0.017842
#>  [4,]  0.129730  0.097712  0.073597  0.055434  0.041753  0.031449  0.023688
#>  [5,]  0.172230  0.129730  0.097712  0.073597  0.055434  0.041753  0.031449
#>  [6,]  0.228670  0.172230  0.129730  0.097712  0.073597  0.055434  0.041753
#>  [7,]  0.303590  0.228670  0.172230  0.129730  0.097712  0.073597  0.055434
#>  [8,]  0.403060  0.303590  0.228670  0.172230  0.129730  0.097712  0.073597
#>  [9,]  0.535130  0.403060  0.303590  0.228670  0.172230  0.129730  0.097712
#> [10,]  0.710460  0.535130  0.403060  0.303590  0.228670  0.172230  0.129730
#> [11,]  0.943250  0.710460  0.535130  0.403060  0.303590  0.228670  0.172230
#> [12,]  1.252300  0.943250  0.710460  0.535130  0.403060  0.303590  0.228670
#> [13,]  1.662600  1.252300  0.943250  0.710460  0.535130  0.403060  0.303590
#> [14,]  2.207400  1.662600  1.252300  0.943250  0.710460  0.535130  0.403060
#> [15,]  2.930700  2.207400  1.662600  1.252300  0.943250  0.710460  0.535130
#> [16,]  3.890900  2.930700  2.207400  1.662600  1.252300  0.943250  0.710460
#> [17,]  5.165800  3.890900  2.930700  2.207400  1.662600  1.252300  0.943250
#> [18,]  6.858400  5.165800  3.890900  2.930700  2.207400  1.662600  1.252300
#> [19,]  9.105600  6.858400  5.165800  3.890900  2.930700  2.207400  1.662600
#> [20,] 12.089000  9.105600  6.858400  5.165800  3.890900  2.930700  2.207400
#> [21,] 16.050000 12.089000  9.105600  6.858400  5.165800  3.890900  2.930700
#> [22,] 21.309000 16.050000 12.089000  9.105600  6.858400  5.165800  3.890900
#> [23,] 16.050000 21.309000 16.050000 12.089000  9.105600  6.858400  5.165800
#> [24,] 12.089000 16.050000 21.309000 16.050000 12.089000  9.105600  6.858400
#> [25,]  9.105600 12.089000 16.050000 21.309000 16.050000 12.089000  9.105600
#> [26,]  6.858400  9.105600 12.089000 16.050000 21.309000 16.050000 12.089000
#> [27,]  5.165800  6.858400  9.105600 12.089000 16.050000 21.309000 16.050000
#> [28,]  3.890900  5.165800  6.858400  9.105600 12.089000 16.050000 21.309000
#> [29,]  2.930700  3.890900  5.165800  6.858400  9.105600 12.089000 16.050000
#>            [,29]
#>  [1,]  0.0076239
#>  [2,]  0.0101220
#>  [3,]  0.0134380
#>  [4,]  0.0178420
#>  [5,]  0.0236880
#>  [6,]  0.0314490
#>  [7,]  0.0417530
#>  [8,]  0.0554340
#>  [9,]  0.0735970
#> [10,]  0.0977120
#> [11,]  0.1297300
#> [12,]  0.1722300
#> [13,]  0.2286700
#> [14,]  0.3035900
#> [15,]  0.4030600
#> [16,]  0.5351300
#> [17,]  0.7104600
#> [18,]  0.9432500
#> [19,]  1.2523000
#> [20,]  1.6626000
#> [21,]  2.2074000
#> [22,]  2.9307000
#> [23,]  3.8909000
#> [24,]  5.1658000
#> [25,]  6.8584000
#> [26,]  9.1056000
#> [27,] 12.0890000
#> [28,] 16.0500000
#> [29,] 21.3090000
#>   Standard Deviations: 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162 4.6162