In hongyuanjia/ggpsychro: A 'ggplot2' Extension for Making Pyschrometric Charts

library(ggpsychro)
knitr::opts_chunk$set(
    collapse = TRUE,
    comment = "#>",
    fig.path = "man/figures/README-",
    fig.align = "center",
    out.width = "60%",
    dev = "png",
    dpi = 100
)

ggpsychro

'ggplot2' extension for making psychrometric charts.

Installation

You can install the development version from GitHub with:

# install.packages("remotes")
remotes::install_github("hongyuanjia/ggpsychro")

Example

The basic

Similar with ggplot2, the creation of a psychrometric chart using ggpsychro starts with function ggpsychro(). You can specify the range of dry-bulb temperature and humidity ratio using tab_lim and hum_lim and the unit system using units

ggpsychro(tdb_lim = c(0, 50), hum_lim = c(0, 50), units = "IP")

You can also create a mollier chart by setting mollier to TRUE.

ggpsychro(mollier = TRUE)

By default, only dry-bulb temperature, humidity ratio and the saturation line are plotted.

The style of the saturation and area above it can be further styled using sat_style and mask_style.

ggpsychro(mask_style = list(fill = "gray"), sat_style = list(color = "black", linetype = 2))

Grid

ggpsychro introduces new ggplot geoms to add 5 more grids onto the base plot:

| Geom | Type | | --- | --- | | geom_grid_relhum | Relative humidity | | geom_grid_wetbulb | Wet-bulb temperature | | geom_grid_vappres | Vaper pressure | | geom_grid_specvol | Specific volume | | geom_grid_enthalpy | Enthalpy |

ggpsychro() +
    geom_grid_relhum() +
    geom_grid_wetbulb() +
    geom_grid_vappres() +
    geom_grid_specvol() +
    geom_grid_enthalpy()

Each of the new geom come along with a corresponding scale_* which can be used to further customize the breaks of each grid

ggpsychro() +
    geom_grid_relhum(alpha = 1.0, label.alpha = 1.0, label.size = 6, label.fontface = 2) +
    scale_relhum(minor_breaks = NULL) +
    geom_grid_wetbulb(size = 1.0, color = "black", alpha = 1.0, label_loc = NA) +
    scale_wetbulb(breaks = seq(25, 30, by = 5), minor_breaks = NULL) +
    geom_grid_vappres(label.size = 5) +
    scale_vappres(breaks = seq(6000, 7000, by = 500), limits = c(6000, 7000)) +
    geom_grid_specvol() +
    scale_specvol(labels = NULL) +
    geom_grid_enthalpy()

Stat

ggpsychro provides 5 new ggplot stats to use together with other common ggplot2 geoms::

| Stat | Type | | --- | --- | | stat_relhum | Relative humidity | | stat_wetbulb | Wet-bulb temperature | | stat_vappres | Vaper pressure | | stat_specvol | Specific volume | | stat_enthalpy | Enthalpy |

This makes it quick easy to add new elements.

Working together with ggplot2 orignal geoms is as simple as change stat to your variable name of interest.

library(eplusr) # for reading EPW data
epw <- read_epw(file.path(eplus_config(8.8)$dir, "WeatherData/USA_CO_Golden-NREL.724666_TMY3.epw"))

ggpsychro(epw$data()[month %in% 5:8]) +
    geom_grid_relhum() +
    geom_point(aes(dry_bulb_temperature, relhum = relative_humidity/100), stat = "relhum", alpha = 0.1) +
    facet_wrap(~month, labeller = as_labeller(function (x) paste0("Month: ", x)))

ggpsychro(tdb_lim = c(10, 35), hum_lim = c(0, 30)) +
    geom_grid_relhum() +
    geom_grid_wetbulb() +
    # 18 wet-bulb line with dry-bulb from 20 - 30
    geom_line(aes(x = 20:30, wetbulb = 18), stat = "wetbulb")

Author

Hongyuan Jia

License

The project is released under the terms of MIT License.

Copyright © 2019-2020 Hongyuan Jia

Contribute

Please note that the 'ggpsychro' project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.

hongyuanjia/ggpsychro documentation built on Feb. 3, 2021, 12:31 p.m.