Roon · December 9, 2015 18:50
diff --git a/README.md b/README.md
diff --git a/wa_lib.R b/wa_lib.R
 #' Basic Wolfram Alpha client and result objects
 library(XML)
 library(plyr)

 WolframClient <- setRefClass(
  "WolframClient",
  fields = list(
    app_id = "character"
  ),
  
  methods = list(
    
    initialize = function(app_id) {
      "initialize Wolfram Alpha Client"
      
      app_id <<- app_id
    },
    
    query = function(query, quiet = TRUE) {
      "run a query against the wolfram alpha database"
      
      message("Querying wolfram alpha...")
      wa_url <- paste0("http://api.wolframalpha.com/v2/query?input=", 
                       URLencode(query), "&appid=", app_id)
      
      destfile <- tempfile()
      download.file(wa_url, destfile, method = "wget", quiet = quiet)
      result <- WolframResult(xmlInternalTreeParse(destfile))
      info <- result$get_info()
      
      if (info$success != "true" || info$error != "false")
        stop("There was a problem with this query. Please check the query infos:\n",
             paste(paste(names(info), info, sep = " = "), collapse = "\n"))
      
      return(result)
    }  
  )
 )

 WolframResult <- setRefClass(
  "WolframResult",
  fields = list(
    doc = "XMLInternalDocument"
  ),
  
  methods = list(
    initialize = function(doc) {
      doc <<- doc
    },
    
    xml = function() doc,
    
    get_info = function() {
      as.list(xpathApply(doc, "//queryresult", xmlAttrs)[[1]])
    },
    
    get_pods = function() {
      xpathApply(doc, "//pod")
    },
    
    get_plaintext = function() {
      ldply(get_pods(), function(pod) {
        data.frame(
          pod = xmlGetAttr(pod, "title"),
          id = xmlGetAttr(pod, "id"),
          plaintext = unlist(xpathApply(pod, "subpod/plaintext", xmlValue))
        )
      })
    }
  )
 )
pod	id	plaintext
Input	Input	pi
Decimal approximation	DecimalApproximation	3.1415926535897932384626433832795028841971693993751058...
Property	Property	pi is a transcendental number
Number line	NumberLine
Continued fraction	ContinuedFraction	[3; 7, 15, 1, 292, 1, 1, 1, 2, 1, 3, 1, 14, 2, 1, 1, 2, 2, 2, 2, 1, 84, 2, 1, 1, 15, ...]
Alternative representations	AlternativeRepresentations:MathematicalFunctionIdentityData	pi = 180 °
Alternative representations	AlternativeRepresentations:MathematicalFunctionIdentityData	pi = -i log(-1)
Alternative representations	AlternativeRepresentations:MathematicalFunctionIdentityData	pi = cos^(-1)(-1)
Series representations	SeriesRepresentations:MathematicalFunctionIdentityData	pi = 4 sum_(k=0)^infinity (-1)^k/(2 k+1)
Series representations	SeriesRepresentations:MathematicalFunctionIdentityData	pi = -2+2 sum_(k=1)^infinity 2^k/(binomial(2 k, k))
Series representations	SeriesRepresentations:MathematicalFunctionIdentityData	pi = sum_(k=0)^infinity (50 k-6)/(2^k binomial(3 k, k))
Integral representations	IntegralRepresentations:MathematicalFunctionIdentityData	pi = 2 integral_0^infinity 1/(t^2+1) dt
Integral representations	IntegralRepresentations:MathematicalFunctionIdentityData	pi = 4 integral_0^1 sqrt(1-t^2) dt
Integral representations	IntegralRepresentations:MathematicalFunctionIdentityData	pi = 2 integral_0^infinity (sin(t))/t dt
pod	id	plaintext
Input interpretation	Input	zinc chloride \| ion equivalents
Result	IonProperties:ChemicalData	Zn^(2+) (zinc) \| 1 Cl^(-) (chloride) \| 2
	#' Basic Wolfram Alpha client and result objects
	library(XML)
	library(plyr)

	WolframClient <- setRefClass(
	"WolframClient",
	fields = list(
	app_id = "character"
	),

	methods = list(

	initialize = function(app_id) {
	"initialize Wolfram Alpha Client"

	app_id <<- app_id
	},

	query = function(query, quiet = TRUE) {
	"run a query against the wolfram alpha database"

	message("Querying wolfram alpha...")
	wa_url <- paste0("http://api.wolframalpha.com/v2/query?input=",
	URLencode(query), "&appid=", app_id)

	destfile <- tempfile()
	download.file(wa_url, destfile, method = "wget", quiet = quiet)
	result <- WolframResult(xmlInternalTreeParse(destfile))
	info <- result$get_info()

	if (info$success != "true" \|\| info$error != "false")
	stop("There was a problem with this query. Please check the query infos:\n",
	paste(paste(names(info), info, sep = " = "), collapse = "\n"))

	return(result)
	}
	)
	)

	WolframResult <- setRefClass(
	"WolframResult",
	fields = list(
	doc = "XMLInternalDocument"
	),

	methods = list(
	initialize = function(doc) {
	doc <<- doc
	},

	xml = function() doc,

	get_info = function() {
	as.list(xpathApply(doc, "//queryresult", xmlAttrs)[[1]])
	},

	get_pods = function() {
	xpathApply(doc, "//pod")
	},

	get_plaintext = function() {
	ldply(get_pods(), function(pod) {
	data.frame(
	pod = xmlGetAttr(pod, "title"),
	id = xmlGetAttr(pod, "id"),
	plaintext = unlist(xpathApply(pod, "subpod/plaintext", xmlValue))
	)
	})
	}
	)
	)