reading json tables
On 12/1/2012 4:08 PM, Duncan Temple Lang wrote:
Hi Michael
The problem is that the content of the .js file is not JSON,
but actual JavaScript code.
You could use something like the following
tt = readLines("http://mbostock.github.com/protovis/ex/wheat.js")
txt = c("[", gsub(";", ",", gsub("var [a-zA-Z]+ = ", "", tt)), "]")
tmp = paste(txt, collapse = "\n")
tmp = gsub("([a-zA-Z]+):", '"\\1":', tmp)
o = fromJSON(tmp)
data = structure(o[1:2], names = c("wheat", "monarch"))
Basically, this
removes the 'var <variable name> =' part
replaces the ; with a , to separate elements
quotes the names of the fields, e.g. year, wheat, wages
puts the two global data objects into a top-level array ([]) container
This isn't ideal (as the regular expressions are not sufficiently specific
and could modify the actual values incorrectly). However, it does the job
for this particular file.
Thanks for this, Duncan I hadn't understood that the data had to be pure JSON. The actual result I want is two data frames, wheat and monarch, whereas fromJSON returns a list of lists. I'll try to figure that part out. -Michael
Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. & Chair, Quantitative Methods York University Voice: 416 736-2100 x66249 Fax: 416 736-5814 4700 Keele Street Web: http://www.datavis.ca Toronto, ONT M3J 1P3 CANADA