R/plot.sizepower.R

In PoweR: Computation of Power and Level Tables for Hypothesis Tests

plot.sizepower <- function(x, xnull, legend.pos = NULL, ...) {

    Fx <- x
    
    Fxnull <- xnull
    
    if(!inherits(Fx, "Fx") | !inherits(Fxnull, "Fx")) stop("Method is only for Fx objects!")

	## Retrieve informations from Fx computed by calcFx()
    Fxi <- Fx$Fx.mat
    xi <- Fx$x
    law <- Fx$law
    statnames <- Fx$statnames
    N <- Fx$N
	
	## Retrieve informations from Fxnull computed by calcFx()
    Fxnull <- Fxnull$Fx
    
	## now we plot these (Fxnull,Fxi) in the same graph. Fxnull = null distribution, Fxi = alternative distribution

	# we trace the 45 degree line
    plot(c(0, 1), c(0, 1), type = "n", main = paste("Size-power curves","\n N = ", N, " & m = ", length(xi), sep = ""),
         sub = paste("Data: ", law, sep = ""), xlab = "size", ylab = "power", asp = 1)
    lines(x = c(0, 1), y = c(0, 1), lty = "dotted", col = 1)
    text(0.9, 0.85, "45 degree line", cex = 1, srt = 45)
	
	# then add theses Size-power curves
    for (i in 1:length(statnames)) {
        points(c(0, Fxnull[, i], 1), c(0, Fxi[, i], 1), type = "l", col = i + 1)
    }
	
	# legend
    if (is.character(legend.pos)) legend(x = legend.pos, legend = statnames, col = 2:(length(statnames) + 1), lty = 1)
    if (is.null(legend.pos)) {
        legend.x <- 0.7
        legend.y <- 0.3
        legend(x = legend.x, y = legend.y, legend = statnames, col = 2:(length(statnames) + 1), lty = 1)
    } else {
        legend(x = legend.pos[1], y = legend.pos[2], legend = statnames, col = 2:(length(statnames) + 1), lty = 1)
    }
    
}