Method: RinRuby#assign

Defined in:

lib/rinruby.rb

#assign(name, value) ⇒ Object

Data is copied from Ruby to R using the assign method or a short-hand equivalent. For example:

>> names = ["Lisa","Teasha","Aaron","Thomas"]
>> R.assign "people", names
>> R.eval "sort(people)"

produces the following :

[1] "Aaron"     "Lisa"     "Teasha" "Thomas"

The short-hand equivalent to the assign method is simply:

>> R.people = names

Some care is needed when using the short-hand of the assign method since the label (i.e., people in this case) must be a valid method name in Ruby. For example, R.copy.of.names = names will not work, but R.copy_of_names = names is permissible.

The assign method supports Ruby variables of type Fixnum (i.e., integer), Bignum (i.e., integer), Float (i.e., double), String, and arrays of one of those three fundamental types. Note that Fixnum or Bignum values that exceed the capacity of R’s integers are silently converted to doubles. Data in other formats must be coerced when copying to R.

Parameters that can be passed to the assign method:

• name: The name of the variable desired in R.

• value: The value the R variable should have. The assign method supports Ruby variables of type Fixnum (i.e., integer), Bignum (i.e., integer), Float (i.e., double), String, and arrays of one of those three fundamental types. Note that Fixnum or Bignum values that exceed the capacity of R’s integers are silently converted to doubles. Data in other formats must be coerced when copying to R.

The assign method is an alternative to the simplified method, with some additional flexibility. When using the simplified method, the parameters of name and value are automatically used, in other words:

>> R.test = 144

is the same as:

>> R.assign("test",144)

Of course it would be confusing to use the shorthand notation to assign a variable named eval, echo, or any other already defined function. RinRuby would assume you were calling the function, rather than trying to assign a variable.

When assigning an array containing differing types of variables, RinRuby will follow R’s conversion conventions. An array that contains any Strings will result in a character vector in R. If the array does not contain any Strings, but it does contain a Float or a large integer (in absolute value), then the result will be a numeric vector of Doubles in R. If there are only integers that are suffciently small (in absolute value), then the result will be a numeric vector of integers in R.

Raises:

• (EngineClosed)

# File 'lib/rinruby.rb', line 402

def assign(name, value)
   raise EngineClosed if @engine.closed?
  if assignable?(name)
    assign_engine(name,value)
  else
    raise ParseError, "Parse error"
  end
end