The gvisMap function reads a data.frame and creates text output referring to the Google Visualisation API, which can be included into a web page, or as a stand-alone page.
Usage
gvisMap(data, locationvar = "", tipvar = "", options = list(), chartid)
Arguments
- data
a
data.frame
. The data has to have at least two columns with location name (locationvar
) and the variable to display the text in the tip icon (tipvar
).- locationvar
column name of
data
with the geo locations to be analysed. The locations can be provide in two formats:- Format 1
'latitude:longitude'. See the example below.
- Format 2
The first column should be a string that contains an address. This address should be as complete as you can make it.
- tipvar
column name of
data
with the string text displayed over the tip icon.- options
list of configuration options for Google Map.
https://developers.google.com/chart/interactive/docs/gallery/map#Configuration_Options
The parameters can be set via a named list. The parameters have to map those of the Google documentation.
Boolean arguments are set to either
TRUE
orFALSE
, using the R syntax.Google API parameters with a single value and with names that don't include a "." are set like one would do in R, that is
options=list(width=200, height=300)
. Exceptions to this rule are the width and height options forgvisAnnotatedTimeLine
andgvisAnnotationChart
. For those two functions, width and height must be character strings of the format"Xpx"
, whereX
is a number, or"automatic"
. For example,options=list(width="200px", height="300px")
.Google API parameters with names that don't include a ".", but require multivalues are set as a character, wrapped in "[ ]" and separated by commas, e.g.
options=list(colors="['#cbb69d', '#603913', '#c69c6e']")
Google API parameters with names that do include a "." present parameters with several sub-options and have to be set as a character wrapped in "{ }". The values of those sub-options are set via parameter:value. Boolean values have to be stated as
'true'
or'false'
. For example the Google documentaion states the formating options for the vertical axis and states the parameter asvAxis.format
. Then this paramter can be set in R as:options=list(vAxis="\{format:'#,###%'\}")
.If several sub-options have to be set, e.g.
titleTextStyle.color
,titleTextStyle.fontName
andtitleTextStyle.fontSize
, then those can be combined in one list item such as:options=list(titleTextStyle="\{color:'red', fontName:'Courier', fontSize:16\}")
paramters that can have more than one value per sub-options are wrapped in "[ ]". For example to set the labels for left and right axes use:
options=list(vAxes="[\{title:'val1'\}, \{title:'val2'\}]")
gvis.editor
a character label for an on-page button that opens an in-page dialog box enabling users to edit, change and customise the chart. By default no value is given and therefore no button is displayed.
- chartid
character. If missing (default) a random chart id will be generated based on chart type and
tempfile
Value
gvisMap
returns list
of class
"gvis
" and "list
".
An object of class "gvis
" is a list containing at least the
following components:
type
Google visualisation type
chartid
character id of the chart object. Unique chart ids are required to place several charts on the same page.
html
a list with the building blocks for a page
header
a character string of a html page header:
<html>...<body>
,chart
a named character vector of the chart's building blocks:
jsHeader
Opening
<script>
tag and reference to Google's JavaScript library.jsData
JavaScript function defining the input
data
as a JSON object.jsDrawChart
JavaScript function combing the data with the visualisation API and user options.
jsDisplayChart
JavaScript function calling the handler to display the chart.
jsFooter
End tag
</script>
.jsChart
Call of the
jsDisplayChart
function.divChart
<div>
container to embed the chart into the page.
caption
character string of a standard caption, including data name and chart id.
footer
character string of a html page footer:
</body>...</html>
, including the used R and googleVis version and link to Google's Terms of Use.
References
Google Chart Tools API: https://developers.google.com/chart/interactive/docs/gallery/map
See also
See also print.gvis
, plot.gvis
for printing and
plotting methods, gvisGeoChart
for an alternative to gvisMap
.
Examples
## Please note that by default the googleVis plot command
## will open a browser window and requires Internet
## connection to display the visualisation.
## Example with latitude and longitude information
## Plot Hurricane Andrew (1992) storm path:
data(Andrew)
M1 <- gvisMap(Andrew, "LatLong" , "Tip",
options=list(showTip=TRUE, showLine=TRUE, enableScrollWheel=TRUE,
mapType='hybrid', useMapTypeControl=TRUE,
width=800,height=400))
plot(M1)
## Example with address, here UK post-code and some html code in tooltip
df <- data.frame(Postcode=c("EC3M 7HA", "EC2P 2EJ"),
Tip=c("<a href='https://www.lloyds.com'>Lloyd's</a>",
"<a href='https://www.guildhall.cityoflondon.gov.uk/'>Guildhall</a>"))
M2 <- gvisMap(df, "Postcode", "Tip",
options=list(showTip=TRUE, mapType='normal',
enableScrollWheel=TRUE))
plot(M2)
## Change mapping icons
M3 <- gvisMap(df, "Postcode", "Tip",
options=list(showTip=TRUE, mapType='normal',
enableScrollWheel=TRUE,
icons=paste0("{",
"'default': {'normal': 'https://icons.iconarchive.com/",
"icons/icons-land/vista-map-markers/48/",
"Map-Marker-Ball-Azure-icon.png',\n",
"'selected': 'https://icons.iconarchive.com/",
"icons/icons-land/vista-map-markers/48/",
"Map-Marker-Ball-Right-Azure-icon.png'",
"}}")))
plot(M3)