'AWS Comprehend' Client Package

Client for 'AWS Comprehend' < https://aws.amazon.com/comprehend>, a cloud natural language processing service that can perform a number of quantitative text analyses, including language detection, sentiment analysis, and feature extraction.

aws.comprehend is a package for natural language processing.

To use the package, you will need an AWS account and to enter your credentials into R. Your keypair can be generated on the IAM Management Console under the heading Access Keys. Note that you only have access to your secret key once. After it is generated, you need to save it in a secure location. New keypairs can be generated at any time if yours has been lost, stolen, or forgotten. The aws.iam package profiles tools for working with IAM, including creating roles, users, groups, and credentials programmatically; it is not needed to use IAM credentials.

By default, all cloudyr packages for AWS services allow the use of credentials specified in a number of ways, beginning with:

1. User-supplied values passed directly to functions.

2. Environment variables, which can alternatively be set on the command line prior to starting R or via an Renviron.site or .Renviron file, which are used to set environment variables in R during startup (see ? Startup). Or they can be set within R:

   Sys.setenv("AWS_ACCESS_KEY_ID" = "mykey",
              "AWS_SECRET_ACCESS_KEY" = "mysecretkey",
              "AWS_DEFAULT_REGION" = "us-east-1",
              "AWS_SESSION_TOKEN" = "mytoken")

3. If R is running an EC2 instance, the role profile credentials provided by aws.ec2metadata.

4. Profiles saved in a /.aws/credentials "dot file" in the current working directory. The `"default" profile is assumed if none is specified.

5. A centralized ~/.aws/credentials file, containing credentials for multiple accounts. The `"default" profile is assumed if none is specified.

Profiles stored locally or in a centralized location (e.g., ~/.aws/credentials) can also be invoked via:

# use your 'default' account credentials
aws.signature::use_credentials()
 
# use an alternative credentials profile
aws.signature::use_credentials(profile = "bob")

Temporary session tokens are stored in environment variable AWS_SESSION_TOKEN (and will be stored there by the use_credentials() function). The aws.iam package provides an R interface to IAM roles and the generation of temporary session tokens via the security token service (STS).

Code Examples

Here are some simple code examples:

library("aws.comprehend")
 
# simple language detection
detect_language("This is a test sentence in English")

##   LanguageCode     Score
## 1           en 0.9945121

# multi-lingual language detection
detect_language("A: ¡Hola! ¿Como está, usted?\nB: Ça va bien. Merci. Et toi?")

##   LanguageCode     Score
## 1           fr 0.6712779
## 2           pt 0.2771675

# sentiment analysis
detect_sentiment("I have never been happier. This is the best day ever.")

##   Index Sentiment       Mixed    Negative    Neutral  Positive
## 1     1  POSITIVE 0.002856119 0.003094881 0.03672606 0.9573229

# named entity recognition
txt <- c("Amazon provides web services.", "Jeff is their leader.")
detect_entities(txt)

##   Index BeginOffset EndOffset     Score   Text         Type
## 1     0           0         6 0.9960732 Amazon ORGANIZATION
## 2     1           0         4 0.9994556   Jeff       PERSON

# key phrase detection
detect_phrases(txt)

##   Index BeginOffset EndOffset     Score         Text
## 1     0           0         6 0.9884282       Amazon
## 2     1          16        28 0.9975396 web services
## 3     0           0         4 0.9950518         Jeff
## 4     1           8        20 0.9918150 their leader

All of the functions accept either a single character string or a character vector.

Installation

This package is not yet on CRAN. To install the latest development version you can install from the cloudyr drat repository:

# latest stable version
install.packages("aws.comprehend", repos = c(cloudyr = "http://cloudyr.github.io/drat", getOption("repos")))

Or, to pull a potentially unstable version directly from GitHub:

if (!require("remotes")) {
    install.packages("remotes")
}
remotes::install_github("cloudyr/aws.comprehend")