ursa (version 3.9.4)

panel_graticule: Add latitude/longitude or metric grid to the image panel.

Description

panel_graticule puts a grid on the panel with raster image. If CRS is georeferenced then grid is generated from longitudes and latitudes.

Usage

panel_graticule(...)
compose_graticule(...)
# non-public
.compose_graticule(panel = 0L, col = "grey70", border = "grey70", lon = NA, lat = NA,
                lwd = 0.5, lty = 2, marginalia = rep(FALSE, 4), trim = FALSE,
                language = NA_character_, cex = 0.75, verbose = FALSE)
# non-public
.panel_graticule(obj, marginalia = rep(TRUE, 4), verbose = FALSE)

Arguments

…

Set of arguments, which are recognized via their names (using regular expressions) and classes:

Matched pattern	Used argument	Description
(graticule|grid(line)*)		Logical. Responsible for should grid lines be displayed or not. If TRUE then grid lines are plotted. If FALSE then grid lines are not displayed. Default is TRUE.
^(graticule|grid(line)*)$	panel	See below.
(graticule|grid(line)\.)*col	col	See below. Default value in compose_graticule depends on panel background color, "#0000002F" for ligth panel background, and "#FFFFFF4F" for dark panel background.
(graticule|grid(line)\.)*border	border	See below. Default value in compose_graticule depends on figure background color, "#0000002F" for ligth figure background, and "#FFFFFF4F" for dark figure background.
(graticule|grid(line)\.)*lon	lon	See below.
(graticule|grid(line)\.)*lat	lat	See below.
(graticule|grid(line)\.)*lwd	lwd	See below.
(graticule|grid(line)\.)*lty	lty	See below.
(decor|margin(alia)*)	marginalia	See below. .compose_graticule and .panel_graticule don't validate correctness of this parameter.
((graticule|grid(line)\.)*trim	trim	See below.
(graticule|grid(line)\.)*language	language	See below.

obj

Objects of the class ursaGridLine. It is internal structure, which is returned by function .compose_graticule.

panel

Integer vector. Panel for which coastline will be displayed. 0L means that coastline will bw displayed for all panels. Default is 0L.

col

Character. Color code/name for grid lines. Default is "grey70".

border

Character. Color code/name for marginal labels and ticks. Default is "grey70".

lon

Numeric vector. Set of longitudes for grid. If NA then set of logitudes is formed internally. Default is NA.

lat

Numeric vector. Set of latitudes for grid. If NA then set of latidudes is formed internally. Default is NA.

lwd

Positive numeric. Width of grid line. Default is 0.5. See lwd in par.

lty

Positive integer. Type (pattern) of grid line. Default is 2 (dashed). See lty in par.

marginalia

Logical or integer vectors. Responsible for whether longitudes and latitudes (or metric coordinates) be labelled on the frame of panel with raster image. If logical and TRUE, then labels will be displatyed on each open side of panel. If logical and FALSE then labels will not be displayed. If logical of length 4, then labels will be displayed on specific side, where side index is c(bottom, left, top, right) (see description for marginal parameters in par). If argument is a vector of positive integers, then labels for grid lines are plotted only for the specified panels, which sequence is defined in compose_design function and returned from getOption("ursaPngLayout")$layout. Default is c(TRUE,TRUE,TRUE,TRUE).

language

Character. Language for longitude and latitude captions. If "ru" then captions are in Russian else in English. Default is NA.

trim

Logical. If grid lines are labelled then trim=TRUE prevents crossing the labels on neighbor perpendicular sides.

cex

Positive numeric. The relative font size for grid lines' labels. Make sence in the case of labels plotting. Default is 0.75.

verbose

Logical. Value TRUE may provide some additional information on console. Default is FALSE.

Value

Function returns NULL value.

Details

If not language="ru" but environmental variable LANGUAGE=ru then labels are in Russian (cyrillics).

Argument gridline (or, grid) is introduced for unconditional calling of panel_graticule inside of high-level functions.

Grid lines can be controlled in high-level plot functions (e.g., display, compose_plot, display_stack, display_brick, display_rgb, etc.). To prevent displaying grid lines, use argument gridline=FALSE (or grid=FALSE). To display grid lines, use argument gridline=TRUE (or grid=TRUE) and prefix grid(line)* (gridline.* or grid.*) for grid lines' parameters, e.g., gridline.verb=TRUE, grid.col="black". If prefix is omitted then arguments with the same names affect in other functions in the part of high-level function.

If grid lines are formed internally, then desirable number of lines for each direction is 3. The design of line density is based on intuition, providing pretty labelling.

If CRS is georeferenced then grid lines are corresponded to longitudes and latitudes. Integer minutes are used to illustate fractional values of degrees. If precision of minutes is insufficient, then integer values of seconds are introduced. The fractional values of seconds are not used.

Labels are located at the points, where grid lines cross plot margin. Labels are not overlapped along the same side. To prevent overlapping along the same side, labels are shifted or omitted. Argument trim=TRUE prevents overlapping labels from neighbor sides via hidding.

Examples

# NOT RUN {
session_grid(NULL)
# }
# NOT RUN {
 ## Changing of environmental variables is out of CRAN Policy 
Sys.setenv(LANGUAGE="ru")
# }
# NOT RUN {
# example no.1
cl <- compose_design(layout=c(2,2),legend=NULL)
session_grid(regrid(lim=3.2*1e6*c(-1,-1,1,1)))
compose_open(cl)
for (i in 1:4) {
   panel_new()
   panel_coastline()
   panel_graticule(decor=TRUE,trim=i %in% c(2:4))
   panel_annotation(text=as.character(i))
   panel_scalebar(scalebar=i==3)
}
compose_close()

# example no.2
session_grid(regrid(lim=1e6*c(-0.5,0.5,1.5,2.5)))
compose_open(layout=c(2,2),legend=NULL,skip=4)
for (i in seq(getOption("ursaPngLayout")$image)) {
   panel_new()
   panel_coastline()
   if (i==1)
      panel_graticule()
   else if (i==2)
      panel_graticule(decor=TRUE,lon=seq(0,360,by=40)[-1],lat=seq(-90,90,by=10))
   else if (i==3)
      panel_graticule(decor=TRUE,lon=seq(0,360,by=20)[-1],lat=seq(-90,90,by=5)
                     ,trim=TRUE)
   else if (i==4)
      panel_graticule(gridline=FALSE)
   panel_scalebar(scalebar=1)
   panel_annotation(text=as.character(i))
}
compose_close()

# example no.3 -- indirect usage
session_grid(NULL)
display(pixelsize(),decor=TRUE,grid.col="green3",coast.col="darkgreen",side=2)

# }
# NOT RUN {
 ## Changing of environmental variables is out of CRAN Policy 
Sys.setenv(LANGUAGE="") # reset environmental variable
# }