glance is a parser of command line arguments for non-public function .glance, which creates multi-panel plots for each attribute of vector file or for each band of raster file.
glance(...)# non-public
.glance(dsn, layer = ".*", grid = NULL, field = ".+", size = NA, expand = 1,
border = 27, lat0 = NA, lon0 = NA, resetProj = FALSE, resetGrid = FALSE,
style = "auto", feature = c("auto", "field", "geometry"), alpha = NA,
basemap.order = c("after", "before"), basemap.alpha = NA,
engine = c("native", "sp", "sf"), geocode = "", place="",
area = c("bounding", "point", "shape"), zoom = NA, gdal_rasterize = FALSE,
silent = FALSE, verbose = FALSE, ...)
Character or object of either ursaRaster, Spatial, or sf classes. If character, then data source name (interpretation varies by driver - for some drivers, dsn is a file name, but may also be a folder, or contain the name and access credentials of a database).
Character or integer. If integer, then layer index. If character, then pattern (regular expressions) to recognize layer by name. Only one layer selection is allowed. If selected more then one layer, the error message contains indices and names of layers. Usually, datasets (e. g., "ESRI Shapefile") have only one layer. Default is ".*"; interpreted as all layers.
Object of class ursaGrid or NULL. Reference CRS and boundary box for visualization. If NULL, then CRS and boundary box are zoomed to layer. Default is NULL.
Character. Pattern for field (attribute, column,...) selection by name using regular expressions. Multiple selection is allowed. Default is ".+"; all fields.
Integer of length 1 or 2 or character of length 1. Size of plotting panel in pixels. If character, then parsed to integer of length 1 or 2. Length 2 is used only for web cartography. If length 1, then size defines width of panel, and height is defined automatically. If integer, then width of panel for plotting in pixels. Default is NA; for web cartogrpaphy value of maximal size of static maps, and code640 for other cases.
Numeric. Multiplier for plotting panel zoom in relation to extent of plotting geometry. Default is 1.0.
Integer. Value in pixels of fixed margins around plotting geometry. Default is 27L.
Numeric. Parallel os zero distortion. If NA, then parallel os zero distortion is determined from object geometry. Actual for "+proj=stere" projections. Default is NA.
Numeric. Central meridian, which have vertical direction on the plot. If NA, then central meridian is determined from object geometry. Default is NA.
Logical. Value TRUE overwrites projection of vector file. Default is FALSE.
Logical. If TRUE, then session grid is ignored, and new session grid is assigned from input file. If FALSE, then input file is nested in the session grid.
Character. Either projection class or source of web-catrogrpaphy for basemap. Specified by a sentence of words separated by spaces.
Projection class
Valid values are "stere", "laea", "merc", "longlat". Default is keyword "auto"; use object projection, if this projection differs from projection class "+longlat", otherwise, projection ("stere" or "merc") is determined internally.
Web cartography.
Static map
Valid values are "google", "openstreetmap", "sputnikmap". Static maps have priority over tile services. however additional word "static" can be specified in the sentence, e.g., "openstreetmap static" or "static google". Additional parameters for request to web-script can be added in the sentence in the form "argument1=value1 [argument2=value2]", e.g., style="google static maptype=terrain language=ru-RU scale=2".
Tile service
Supported tile services can be returned by calling of non-public function ursa:::.tileService() without arguments. Valid values are "mapnik", "cycle", "transport", "mapsurfer", "sputnik", "thunderforest", "carto", "kosmosnimki", etc.
By default, if data has no data fields (e. g., geometry only), then basemap is drawn in color, else in grayscale. Adding word "color" (or "colour") to the sentence forces to use colored basemap. Adding word "gray" (or "grey", "greyscale", "grayscale") to the sentence forces to use colored basemap.
The order of words in the sentence is any.
Keywords "google", "openstreetmap" force to use "Google Static Map" or "OpenStreetMap static map images" for basemap; the resulted projection has class "+proj=merc".
Character. Appearance of visualization. If "field" then data of each field is plotted on separate panel (number of panels is equal to number of columns in attribute table). If "geometry" then each feature is plotted on separate panel (number of panels is equal to number of rows in attribute table). Default is "auto"; if intersects of features are found, then "geometry" is used, else "field".
Character. The order of basemap layer rendering in the case of web-cartography basemap.If "before", then basemap is plotted before object plot. If "after", then basemap is plotted over object.
Character. The saturation of basemap in the case of web-cartography basemap. Default is NA; basemap.alpha=0.5 for basemap.order="before" and basemap.alpha=0.35 for basemap.order="after".
Character. The opacity of plotted object. Default is NA; 0.75 for basemap.order="before" in web-cartogrpaphy style, 1.00 - in all other cases.
Character keyword. Forcing to vector files processing by functions from package sp (engine="sp") or package sf (engine="sf", if sf is installed). Default is "native"; if dsn is Spatial object or if sf is not installed, then "sp" is used.
Character. Keyword for geocode service. Valid values are "google", "nominatim". If dsn is character and file dsn not found, then trying to interpret dsn as a request to geocode service. The output is only basemap of web cartogrpaphy. Default is ""; several services are considered in the case of failure. Is style is not specified, then "Google Static Map" is used for geocode="google", and "OpenStreetMap static map images" for geocode="nominatim".
Character. Type of geographical object (river, island) in the geocoding request. If geocode service is "nominatim", then place is searched among attributes "class" and "type". Default is ""; any object is acceptable.
Character. Keyword of spatial class of geocoded object. "bounding" is used for boundary box; "point" is used for point. Default value is extracted by match.arg(area).
Positive integer or character. Zooming if web-cartography is applied for basemap. If integer, then value of zoom for tile services and staticmap. If character, then "0" means zoom by default (defined internally), "+1" means increment on 1 of default zoom, "+2" means zoom increment on 2, "-1" means zoom decrement on 1, "-2" means zoom decrement on 2, etc. Default is NA; zoom is defined internally.
Logical. If TRUE and GDAL utilities are in the system search path, then overlay for panels is formed via rastetization of vector file. GDAL utility "gdal_rasterize" is used. Note, that GDAL (system level) is optional for this package. Default is FALSE.
Logical. Value TRUE cancels progress bar. Default is FALSE.
Logical. Logical. Value TRUE may provide some additional information on console. Default is FALSE.
glance returns integer: 0L - successful, 10L - call without arguments.
Command line usage implies set of arguments using pair: argument name and argument value. and values in the format "[name1=]value1 [name2]=value2". No spaces around = (equal symbol). Argument name can be omitted, symbol = is omitted too. If argument value has spaces, then argument value should be surrounded by double quotes (fname="my test.shp"). If argument value is matched to R function, then such value should be surrounded by single quotes (layer='density').
Command line usage example: Rscript -e ursa::glance() 'final_more_than_032.sqlite' attr="select" resetProj=TRUE expand=1.5
For OS Windows, bat-file can be created for raster and vector file association:
Rscript -e ursa::glance() %*
Command line usage implies external software for PNG view session_pngviewer(TRUE).
# NOT RUN {
session_grid(NULL)
f <- system.file("vectors","scot_BNG.shp",package="rgdal")
glance(f,style="merc",field="(NAME|COUNT)")
cmd <- paste("Rscript --vanilla -e ursa::glance()",paste0("\"",f,"\"")
,"style=\"merc\"","field=\"(lon|lat)\"")
cat(" --------- Try in command line: -----------\n")
message(cmd)
cat(" ----------- end of quoting ---------------\n")
# }
# NOT RUN {
## windows: figure will be opened using *.png file association
try(system(cmd,wait=FALSE))
# }
# NOT RUN {
require(sp)
a <- data.frame(lat=c(70.734,71.657),lon=c(178.577,-177.38),place="Wrangel Island")
coordinates(a) <- ~lon+lat
proj4string(a) <- "+init=epsg:4326"
# }
# NOT RUN {
## internet connection is required
glance(a,style="google color maptype=terrain")
# }
# NOT RUN {
## internet connection is required
glance(a,style="openstreetmap color")
# }
# NOT RUN {
## internet connection is required
glance(a,style="mapnik color tile")
# }
# NOT RUN {
## internet connection is required
glance("Svalbard")
# }
Run the code above in your browser using DataLab