weblmCalculateConditionalProbability function

Calculates the conditional probability that a word follows a sequence of words.

This function calculates the conditional probability that a particular word will follow a given sequence of words. The input string must be in ASCII format.

Internally, this function invokes the Microsoft Cognitive Services Web Language Model REST API documented at https://www.microsoft.com/cognitive-services/en-us/web-language-model-api/documentation.

You MUST have a valid Microsoft Cognitive Services account and an API key for this function to work properly. See https://www.microsoft.com/cognitive-services/en-us/pricing

for details.

weblmCalculateConditionalProbability(precedingWords, continuations,
  modelToUse = "body", orderOfNgram = 5L)

Arguments

• precedingWords: (character) Character string for which to calculate continuation probabilities. Must be in ASCII format.
• continuations: (character vector) Vector of words following precedingWords for which to calculate conditional probabilities.
• modelToUse: (character) Which language model to use, supported values: "title", "anchor", "query", or "body" (optional, default: "body")
• orderOfNgram: (integer) Which order of N-gram to use, supported values: 1L, 2L, 3L, 4L, or 5L (optional, default: 5L)

Returns

An S3 object of the class weblm. The results are stored in the results dataframe inside this object. The dataframe contains the continuation words and their log(probability).

Examples

## Not run:

 tryCatch({

   # Calculate conditional probability a particular word will follow a given sequence of words
   conditionalProbabilities <- weblmCalculateConditionalProbability(
     precedingWords = "hello world wide",       # ASCII only
     continuations = c("web", "range", "open"), # ASCII only
     modelToUse = "title",                      # "title"|"anchor"|"query"(default)|"body"
     orderOfNgram = 4L                          # 1L|2L|3L|4L|5L(default)
   )

   # Class and structure of conditionalProbabilities
   class(conditionalProbabilities)
   #> [1] "weblm"

   str(conditionalProbabilities, max.level = 1)
   #> List of 3
   #>  $ results:'data.frame':  3 obs. of  3 variables:
   #>  $ json   : chr "{"results":[{"words":"hello world wide","word":"web", __truncated__ }]}
   #>  $ request:List of 7
   #>   ..- attr(*, "class")= chr "request"
   #>  - attr(*, "class")= chr "weblm"

   # Print results
   pandoc.table(conditionalProbabilities$results)
   #> -------------------------------------
   #>      words        word   probability
   #> ---------------- ------ -------------
   #> hello world wide   web      -0.32
   #>
   #> hello world wide range     -2.403
   #>
   #> hello world wide  open      -2.97
   #> -------------------------------------

 }, error = function(err) {

   # Print error
   geterrmessage()

 })
## End(Not run)

Author(s)

Phil Ferriere pferriere@hotmail.com