1\name{GetMap.bbox}
2
3\alias{GetMap.bbox}
4
5\title{GetMap bbox}
6
7\description{Wrapper function for \link{GetMap}. Query the Google server for a static map tile, defined primarily by its lat/lon range and/or center and/or zoom.
8
9Multiple additional arguments allow the user to customize the map tile.}
10
11\usage{GetMap.bbox(lonR, latR, center, size = c(640, 640),
12
13    destfile = "MyTile.png", MINIMUMSIZE = FALSE, RETURNIMAGE = TRUE,
14
15    GRAYSCALE = FALSE, NEWMAP = TRUE, zoom, verbose = 0,
16
17    SCALE = 1, type = c("google", "google-m", "google-s",
18
19        "osm", "osm-hot", "stamen-toner", "stamen-terrain",
20
21        "stamen-watercolor")[1], urlBase = "http://mt1.google.com/vt/lyrs=m",
22
23    tileDir = "/tmp/", ...)}
24
25\arguments{
26
27  \item{lonR}{longitude range}
28
29  \item{latR}{latitude range}
30
31  \item{center}{optional center}
32
33  \item{size}{desired size of the map tile image. defaults to maximum size returned by the Gogle server, which is 640x640 pixels}
34
35  \item{destfile}{File to load the map image from or save to, depending on \code{NEWMAP}.}
36
37  \item{MINIMUMSIZE}{reduce the size of the map to its minimum size that still fits the lat/lon ranges ?}
38
39  \item{RETURNIMAGE}{return image yes/no default: TRUE}
40
41  \item{GRAYSCALE}{Boolean toggle; if TRUE the colored map tile is rendered into a black & white image, see \link{RGB2GRAY}}
42
43  \item{NEWMAP}{if TRUE, query the Google server and save to \code{destfile}, if FALSE load from destfile.}
44
45  \item{zoom}{Google maps zoom level. optional}
46
47  \item{verbose}{level of verbosity}
48
49  \item{SCALE}{use the API's scale parameter to return higher-resolution map images. The scale value is multiplied with the size to determine the actual output size of the image in pixels, without changing the coverage area of the map}
50
51  \item{type}{choice of tile server}
52
53  \item{urlBase}{tileserver URL, alternatives would be "http://a.tile.openstreetmap.org/", "http://tile.stamen.com/toner/","http://tile.stamen.com/watercolor/"}
54
55  \item{tileDir}{map tiles can be stored in a local directory, e.g. "~/mapTiles/Google/"}
56
57  \item{\dots}{extra arguments to \link{GetMap}}
58
59}
60
61
62
63\value{map tile}
64
65
66
67\author{Markus Loecher}
68
69
70
71
72
73
74
75
76
77\examples{
78
79 if (0){
80
81 	mymarkers <- cbind.data.frame(lat = c(38.898648,38.889112, 38.880940),
82
83          lon = c(-77.037692, -77.050273, -77.03660), size =  c('tiny','tiny','tiny'),
84
85          col = c('blue', 'green', 'red'), char = c('','',''));
86
87
88
89	##get the bounding box:
90
91  	bb <- qbbox(lat = mymarkers[,"lat"], lon = mymarkers[,"lon"]);
92
93
94
95	##download the map:
96
97  	MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "DC.png", GRAYSCALE =TRUE,
98
99                markers = mymarkers);
100
101 	##The function qbbox() basically computes a bounding box for the given lat,lon
102
103   #points with a few additional options such as quantile boxes, additional buffers, etc.
104
105  	bb <- qbbox(c(40.702147,40.711614,40.718217),c(-74.015794,-74.012318,-73.998284),
106
107            TYPE = "all", margin = list(m=rep(5,4), TYPE = c("perc", "abs")[1]));
108
109 	##download the map:
110
111	MyMap <- GetMap.bbox(bb$lonR, bb$latR,destfile = "MyTile3.png", maptype = "satellite")
112
113
114
115}
116
117}
118
119