Plot svyplan objects

Visualize sampling fractions per stratum or power curves from svyplan results.

Usage

# S3 method for class 'svyplan_strata'
plot(x, ...)

# S3 method for class 'svyplan_power'
plot(x, npoints = 101L, ...)

Arguments

x

A svyplan object.

...

Additional graphical parameters passed to barplot() (for strata) or plot() (for power). These override the defaults, so you can set main, col, ylab, xlab, ylim, etc.

npoints

Number of points in the power curve grid (default 101).

Value

x, invisibly.

Details

plot.svyplan_strata() draws a bar chart of per-stratum sampling fractions (f_h = n_h / N_h) using barplot(). This shows how intensively each stratum is sampled — under Neyman allocation, high-variance strata get higher fractions. A dashed horizontal line marks the overall sampling fraction (n / N). Defaults: col = "grey40", ylab = "Sampling fraction (f_h)", las = 2.

plot.svyplan_power() draws the power-vs-sample-size curve using plot(). The solved point is shown as a filled dot, with dashed reference lines at the computed power and sample size, and a dotted line at the significance level. Defaults: ylim = c(0, 1), type = "l", xlab = "Sample size (per group)", ylab = "Power".

Examples

# Sampling fraction per stratum
set.seed(1)
sb <- strata_bound(rlnorm(2000, 6, 1), n_strata = 4, n = 200,
                    method = "cumrootf")
plot(sb)


# Custom colour
plot(sb, col = "steelblue")


# Power curve with defaults
pw <- power_prop(p1 = 0.30, p2 = 0.40, power = 0.80)
plot(pw)


# Custom line width and colour
plot(pw, lwd = 2, col = "darkred")