# NOT RUN {
# Look at the relationship between power and sample size for the t-test for
# liner trend, assuming a scaled slope of 0.1 and a 5% significance level:
dev.new()
plotLinearTrendTestDesign()
#==========
# Plot sample size vs. the scaled minimal detectable slope for various
# levels of power, using a 5% significance level:
dev.new()
plotLinearTrendTestDesign(x.var = "slope.over.sigma", y.var = "n",
ylim = c(0, 30), main = "")
plotLinearTrendTestDesign(x.var = "slope.over.sigma", y.var = "n",
power = 0.9, add = TRUE, plot.col = "red")
plotLinearTrendTestDesign(x.var = "slope.over.sigma", y.var = "n",
power = 0.8, add = TRUE, plot.col = "blue")
legend("topright", c("95%", "90%", "80%"), lty = 1, bty = "n",
lwd = 3 * par("cex"), col = c("black", "red", "blue"))
title(main = paste("Sample Size vs. Scaled Slope for t-Test for Linear Trend",
"with Alpha=0.05 and Various Powers", sep="\n"))
#==========
# Clean up
#---------
graphics.off()
# }
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