issue with setting up omega with a vector variable

[snailittle]

I tried to save the omega values into vector and use that in "lotri" to set up the omega, which caused an error. Please see below. I can't explicitly write out the omega as usually done because I am implementing it in shiny, and it will have to be passed around with a vector

the usual way which works:

omega<- lotri(eta.KA+eta.CL+eta.V2+eta.Q+eta.V3~c(0.1,
0,0.1,
0,0.06,0.1,
0,0.04,0.04,0.1,
0,0.02,0.02,0.04,0.1))

My way which didn't work

etacov=c(0.1,
0,0.1,
0,0.06,0.1,
0,0.04,0.04,0.1,
0,0.02,0.02,0.04,0.1)
omega <- lotri(eta.KA+eta.CL+eta.V2+eta.Q+eta.V3~ etacov)
Error in dimnames(.ret) <- list(.env$names, .env$names) :
length of 'dimnames' [1] not equal to array extent

[mattfidler]

I can reproduce this issue:

library(lotri)
etacov=c(0.1,
          0,0.1,
          0,0.06,0.1,
          0,0.04,0.04,0.1,
          0,0.02,0.02,0.04,0.1)
omega <- lotri(eta.KA+eta.CL+eta.V2+eta.Q+eta.V3~ etacov)
#> Error in dimnames(.ret) <- list(env$names, env$names): length of 'dimnames' [1] not equal to array extent

^{Created on 2021-05-18 by the reprex package (v2.0.0)}

I believe this is because lotri uses nonstandard evaluation and this isn't supported yet. You could always use the following instead:

library(lotri)
library(backports)
etacov=c(0.1,
          0,0.1,
          0,0.06,0.1,
          0,0.04,0.04,0.1,
          0,0.02,0.02,0.04,0.1)
omega <- eval(parse(text=paste0("lotri(eta.KA+eta.CL+eta.V2+eta.Q+eta.V3~",
                deparse1(etacov), ")")))

omega
#>        eta.KA eta.CL eta.V2 eta.Q eta.V3
#> eta.KA    0.1   0.00   0.00  0.00   0.00
#> eta.CL    0.0   0.10   0.06  0.04   0.02
#> eta.V2    0.0   0.06   0.10  0.04   0.02
#> eta.Q     0.0   0.04   0.04  0.10   0.04
#> eta.V3    0.0   0.02   0.02  0.04   0.10

^{Created on 2021-05-18 by the reprex package (v2.0.0)}

This reprex requires R 4.0 or a recent version of backports. If you don't have either you can define deparse1 manually as:

deparse1 <-function (expr, collapse = " ", width.cutoff = 500L, ...)  {
  paste(deparse(expr, width.cutoff, ...), collapse = collapse)
}