gvis Methods: Print and plot gvis objects

Description

Methods to print and plot gvis objects

Usage

## S3 method for class 'gvis':
print(x, tag="html", file = "", ...)
		
## S3 method for class 'gvis':
plot(x,...)

Arguments

An object of class gvis.

tag

name tag of the objects to be extracted from gvis objects. The default tag "html" will show a complete web page with the visualisation. The tag "chart" will present all code for the visualisation chart only. For more information see the detail

file

file name to be used internally by cat. If "" (the default), output will be printed to the standard output connection, the console unless redirected by sink

...

arguments passed on to cat (print.gvis) or browseURL (plot.gvis).

Value

print.gvisNone (invisible NULL).
plot.gvisReturns the file name invisibly.

Details

An object of class "gvis" is a list containing at least the following components (tags): [object Object],[object Object],[object Object]

References

Please see also the package vignette for the usage of the googleVis package with RApache and R.rsp.

Examples

Run this code

M <- gvisMotionChart(Fruits, "Fruit", "Year")
str(M)
## The output for a complete web page
M

## Access only the plot,
M$html$chart

## wrap it in cat and it becomes more readable,
cat(unlist(M$html$chart))

## or use the print function.
print(M, "chart")

## Extract the data as a JavaScript function.
print(M, "jsData")

## Display the visualisation.
## A web browser with Internet connection and Flash is required.
plot(M)

## Combine with another chart, e.g. table
tbl <- gvisTable(Fruits, options=list(height=220))
Mtbl <- gvisMerge(M, tbl)
plot(Mtbl)

## Suppose you have an existing web page in which you embedded a
  ## motion chart with the id "mtnc".
  ## Now you have a new set of data, but you would like to avoid
  ## touching the html file again.
  ## The idea is to write the data and JavaScript functions into separate
  ## files and to refer to these in the html page.

  ## In this example we call the chart id "mtnc"
  ## To display the example we use the R HTTP server again, and
  ## write the files into a temp directory

  myChartID <- "mtnc"
  ## baseURL should reflect your web address, e.g. http://myHomePage.com
  baseURL <- sprintf("http://127.0.0.1:%s/custom/googleVis", tools:::httpdPort)
  wwwdir <- tempdir() ## the www repository on you computer

  
  ## Create a motion chart
  M=gvisMotionChart(Fruits, "Fruit", "Year", chartid=myChartID)

  ## Here is our plot again
  plot(M)

  ## Write the data and functions into separate files:
  cat(M$html$chart['jsData'], file=file.path(wwwdir, "gvisData.js"))
  cat(M$html$chart[c('jsDrawChart', 'jsDisplayChart', 'jsChart')], 
  				    file=file.path(wwwdir, "gvisFunctions.js"))

  
  ## Create a html page with reference to the above
  ## JavaScript files
  
  html <- sprintf('
  <html>
  <head>
  <script type="text/javascript" src="http://www.google.com/jsapi">
  </script>
  <script type="text/javascript" src="%s/gvisFunctions.js"></script>
  <script type="text/javascript" src="%s/gvisData.js"></script>
  <script type="text/javascript">
  displayChart%s()
  </script>
  </head>
  <body>
  <div id="%s" style="width: 600px; height: 500px;"></div>
  </body>
  </html>
  ', baseURL, baseURL, myChartID, myChartID)
  
  ## Write html scaffold into a file
  cat(html, file=file.path(wwwdir, paste("Chart", myChartID, ".html", sep="")))

  ## Display the result via
  URL <- paste(baseURL,"/Chart", myChartID, ".html", sep="")
  browseURL(URL)

  ## Update the data, say the data should have shown North and South
  ## instead of East and West as a location  
  FruitsUpdate <- Fruits
  levels(FruitsUpdate$Location)=c("North", "South")

  Mupdate=gvisMotionChart(FruitsUpdate, "Fruit", "Year", chartid=myChartID)

  ## Only update the file gvisData.js:
  cat(Mupdate$html$chart['jsData'], file=file.path(wwwdir, "gvisData.js"))

  ## Redisplay the chart with the updated data
  browseURL(URL)

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