Add a psychrometric protractor

geom_psychro_protractor() adds a heat-moisture ratio and sensible heat ratio reference protractor to the mask area of a ggpsychro() plot. The orientation is determined by the parent chart: regular psychrometric charts place the protractor in the upper-left mask area, while Mollier charts rotate the same protractor geometry into the lower-right mask area. guide_psychro_protractor() configures the protractor ticks and labels.

Usage

geom_psychro_protractor(
  ...,
  show = TRUE,
  label = TRUE,
  annotation = TRUE,
  scale = 1,
  radius = 0.24,
  margin = 0.08,
  guide = guide_psychro_protractor()
)

guide_psychro_protractor(
  shr_breaks = waiver(),
  shr_minor_breaks = waiver(),
  shr_labels = waiver(),
  ratio_breaks = waiver(),
  ratio_minor_breaks = waiver(),
  ratio_labels = waiver(),
  check_overlap = TRUE
)

Arguments

...

Line style settings passed to ggplot2::element_line(), such as colour, color, linewidth, size, and linetype. Label style settings can be supplied with label.* names, such as label.colour, label.color, label.size, label.alpha, label.family, and label.fontface.

show

A single logical value. If FALSE, hide the protractor.

label

A single logical value. If FALSE, hide protractor labels.

annotation

A single logical value, character vector, or expression vector. If FALSE, hide the helper formula text. Character and expression vectors must have length 2 and are used as the helper formula labels.

scale

A single positive number for overall protractor scaling. It multiplies radius, protractor line width, and label text size; margin is not scaled.

radius

A single number in panel coordinates controlling the protractor radius.

margin

A single number or length-2 numeric vector in panel coordinates controlling the distance from the mask-area edge. When length 2, the values are horizontal and vertical margins, respectively.

guide

A protractor guide created by guide_psychro_protractor().

shr_breaks, shr_minor_breaks

Numeric vectors controlling the labelled and unlabelled ticks for the sensible heat ratio axis. Use NULL to hide that tick tier.

shr_labels, ratio_labels

A character vector, expression vector, function, NULL, or waiver() controlling labels for the corresponding major breaks. waiver() uses the default numeric labels, and NULL hides the labels.

ratio_breaks, ratio_minor_breaks

Numeric vectors controlling the labelled and unlabelled ticks for the heat-moisture-ratio axis (dh/dW). Use waiver() for the ASHRAE-style defaults, or NULL to hide that tick tier.

check_overlap

A single logical value. If TRUE, overlapping protractor labels are dropped by the grid text grob.

Value

A ggplot addition.

Examples

# Draw the default protractor on a psychrometric chart.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30)) +
    geom_psychro_protractor()


# Draw the protractor in Mollier orientation.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30), mollier = TRUE) +
    geom_psychro_protractor()


# Customize major tick breaks with a guide.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30)) +
    geom_psychro_protractor(
        guide = guide_psychro_protractor(
            shr_breaks = seq(0, 1, by = 0.25),
            ratio_breaks = c(0, 2000, 4000)
        )
    )


# Hide the helper formula annotations.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30)) +
    geom_psychro_protractor(annotation = FALSE)


# Scale and move the protractor inside the mask area.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30)) +
    geom_psychro_protractor(scale = 1.2, margin = c(0.03, 0.10))


# Supply custom labels for selected sensible heat ratio ticks.
ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 30)) +
    geom_psychro_protractor(
        guide = guide_psychro_protractor(
            shr_breaks = c(0, 0.5, 1),
            shr_labels = c("0", "half", "1")
        )
    )