pdDiag() has errors

[mattfidler]

From here:

nlmixrdevelopment/nlmixr#580 (comment)

lotri::lotri({
    temax <- -9.91
    ted50 <- 11.9
    eta.emax ~ pdDiag(2.9)
    add.err <-12.7
})
#> �[1mlotri syntax error:
#> ================================================================================�[0m
#> �[1m:001�[0m: temax <- -9.91
#> �[1m:002�[0m: ted50 <- 11.9
#> lotri error:
#>    bad matrix expression: 'eta.emax ~ pdDiag(2.9)'
#>      matrix expression should be 'name ~ c(lower-tri)'
#> �[1m:003�[0m: eta.emax ~ pdDiag(2.9)
#> �[1m:004�[0m: add.err <- 12.7
#> �[1m================================================================================�[0m
#> Error: lotri syntax errors above

^{Created on 2022-12-13 with reprex v2.0.2}

from @hrishikesh1985

[mattfidler]

Hi @hrishikesh1985,

This is because that pdDiag() does not produce a numeric value. That is what is required for this function. Perhaps a better error would be helpful here...

[mattfidler]

This works though,

lotri::lotri({
    temax <- -9.91
    ted50 <- 11.9
    eta.emax ~ 7.389056
    add.err <-12.7
})
#> Lotri Estimates (get with `lotriEst()`):
#>      name lower   est upper   fix label backTransform
#> 1   temax  -Inf -9.91   Inf FALSE  <NA>          <NA>
#> 2   ted50  -Inf 11.90   Inf FALSE  <NA>          <NA>
#> 3 add.err  -Inf 12.70   Inf FALSE  <NA>          <NA>
#> 
#> Matrix:
#>          eta.emax
#> eta.emax 7.389056

^{Created on 2022-12-13 with reprex v2.0.2}

Or if you still want a single element matrix, then:

library(nlme)
library(lotri)
#> Warning: package 'lotri' was built under R version 4.2.2
lotri::lotri({
    temax <- -9.91
    ted50 <- 11.9
    eta.emax ~ as.numeric(as.matrix(pdDiag(1)))
    add.err <-12.7
})
#> Lotri Estimates (get with `lotriEst()`):
#>      name lower   est upper   fix label backTransform
#> 1   temax  -Inf -9.91   Inf FALSE  <NA>          <NA>
#> 2   ted50  -Inf 11.90   Inf FALSE  <NA>          <NA>
#> 3 add.err  -Inf 12.70   Inf FALSE  <NA>          <NA>
#> 
#> Matrix:
#>          eta.emax
#> eta.emax 7.389056

^{Created on 2022-12-13 with reprex v2.0.2}

[mattfidler]

pdDiag() is not how matrices are specified in nlmixr2

[hrishikesh1985]

Hi Matthew,

as.numeric(as.matrix(pdDiag(1))) works !!!

Thanks for the quick support and response as ever...