legend2: Draws a legend

In choisy/poseid: Population-based Observational Studies of the Epidemiology of Infectious Diseases

Description

Draws a scale legend

Usage

legend2(x, y, legend, col, locate = FALSE, pos = "top-left",
  n_round = 0, col_na = NULL, size_na = 0.075, postext = "left",
  h = 0.75, w = 0.75, tl = 0.2, s = 0.2, ...)

Arguments

x	A numeric value for the x coordinate of the top-left part of the legend
y	A numeric value for the y coordinate of the top-left part of the legend
legend	A character or expression vector to appear in the legend.
col	A vector of colors, if there are too few elements to fill the legend, the elements in col are recycled.
locate	A boolean, if TRUE, call the function locator to indicate the top-left point of the legend
pos	A character, by default top-left, but can be "top-right", "bottom-left" or "bottom-right", used to indicate the position of the scale legend if x, y are not indicated
n_round	An integer indicating the number of significant digits to be used, by default 0.
col_na	the color with which to represent the missing values (by default col_na = NULL). If specified, a NA value will be add to the legend with the color corresponding.
size_na	A numeric value expressing the size of the rectangle for the missing value, expressed in a proportion of the scale legend (between 0 and 1, by default size_na = 0.075)
postext	A character defining the side of the legend text, by default left but can be right
h	A numeric expressing the height of one rectangle in the legend
w	A numeric expressing the width of the legend
tl	A numeric expressing the length of the tick
s	A numeric parameter expressing the space between the text and the tick
...	if need to imput more text parameters for the legend

Details

The number of rectangle in the scale legend is calculate with the number of color in the vector col.

If arguments x,y are not filled, the location may also be specified by setting the parameter pos to a keyword form the list: "top-left", "top-right", "bottom-left" or "bottom-right". This places the legend on the inside of the plot frame at the giver location.

Note that a call to the function locator(1) can be used via setting the parameter locate to TRUE in place of the x and y arguments.

If the length of the vector legend is higher than 12, the axis legend will be calculate with the R break algorithm as implemented in pretty.

Examples

library(gdpm)
library(magrittr)
library(gadmVN)

# dengue data
dengue <- getid(dengue, from = 1992, to = 2010)
# geographic data
map <- gadmVN::gadm(date = 1992, merge_hanoi = TRUE) %>% sf::as_Spatial()
# preparation of the data
library(dplyr)
dengue_0993  <- filter(dengue, year == 1993, month == "September")
dengue_0993 <- select(dengue_0993, province, contains("incidence"))

a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
# By default, col = heat.colors(6) in choromap function
legend2(97, 22.5 ,a ,col = heat.colors(6))

# By default, the legend is on the top left of the figure if x and y are not
# filled, but the position can be easily change by using the parameters pos:
# top left
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6))
# top right
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6), pos = "top-right")
# bottom left
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6), pos = "bottom-left")
# bottom right
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6), pos = "bottom-right")

# By default, the legend text is on the left of the scale, but the
# position can be easily change by using the parameters postext:
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6), pos = "bottom-right",
         postext = "right")

# Printing the color of the missing values:
a <- choromap(dengue_0993, map, fixedBreaks = c(0,10,50,100,500,1000,2000))
legend2(legend = a, col = heat.colors(6), col_na = "grey")

# Changing the number of decimal:
a <- choromap(dengue_0993, map,
               fixedBreaks = c(0, 0.5, 5, 50, 150, 1000, 2000))
legend2(legend = a, col = heat.colors(6), col_na = "grey", n_round = 1)

# Changing the text parameters:
a <- choromap(dengue_0993, map,
               fixedBreaks = c(0, 0.5, 5, 50, 150, 1000, 2000))
legend2(legend = a, col = heat.colors(6), col_na = "grey", n_round = 2,
         cex = 0.8)

# Changing the parameters of the scale:
a <- choromap(dengue_0993, map,
               fixedBreaks = c(0, 0.5, 5, 50, 150, 1000, 2000))
legend2(legend = a, col = heat.colors(6), col_na = "grey",
         h = 0.5, w = 0.4, cex = 0.6)

# Using the locator to choose where to print the legend
## Not run: 
choromap(dengue_0993, map)
legend2(legend = a, col = heat.colors(6), locate = TRUE)

## End(Not run)

choisy/poseid documentation built on Aug. 22, 2019, 4:45 a.m.