[R] Problem with contour(): typo

[Duncan Murdoch]

You're doing a lot of manipulation of the z matrix; I haven't followed 
all of it, but that's where I'd look for problems.  Generally if you 
keep your calculation of the z matrix very simple you are better off. 
For example, once you have xs and ys in the form you want, calculate z as

z <- outer(x,y, function(x,y) ...)

and then plot it using contour(x, y, z, ...)

The only tricky issue here is that the function needs to be vectorized, 
so if your power.TOST function doesn't accept vectors for CV and theta0,
you'll need to put it in a wrapper that does (perhaps using the 
Vectorize function).

Duncan Murdoch



On 28/09/2020 3:08 p.m., Helmut Schütz wrote:
> Dear all,
> 
> sorry, my last message contained a typo. Correct:
> 
> library(PowerTOST)
> x    <- 0.90
> y    <- 0.35
> res  <- as.numeric(sampleN.TOST(theta0 = x, CV = y, design = "2x2x4",
>                                    method = "central", details = FALSE,
>                                    print = FALSE)[7:8])
> mesh <- 28
> ys   <- unique(sort(c(y, seq(y*.8, y*1.2, length.out = mesh))))
> xs   <- unique(sort(c(x, seq(x*0.95, 1, length.out = mesh))))
> z    <- matrix(nrow = length(ys), ncol = length(xs),
>                   dimnames = list(paste0("y.", signif(ys, 5)),
>                                   paste0("x.", signif(xs, 5))))
> for (i in seq_along(ys)) {
>      for (j in seq_along(xs)) {
>        z[i, j] <- suppressMessages(
>                     power.TOST(CV = ys[i], theta0 = xs[j], design = "2x2x4",
>                                method = "central", n = res[1]))
>      }
> }
> z    <- z[nrow(z):1, ncol(z):1]               # reverse rows & columns
> z[paste0("y.", y), paste0("x.", x)] == res[2] # should be TRUE
> contour(xs, ys, z, nlevels = 20, las = 1, labcex = 1,
>            xlab = "x", ylab = "y", main = paste("n =", res[1]))
> abline(h = y, v = x, lty = 2)
> points(x, y, col = "red", cex = 1.5)
> text(x, y, labels = signif(z[paste0("y.", y), paste0("x.", x)], 6),
>         col = "red", adj = c(-0.1, 1.5))
> 
> 
> Helmut
>