Chapters:
1: Introduction
2: Simple example
3: Invocation
4: Finer Control
5: X-Y Plots
6: Contour Plots
7: Image Plots
8: Examples
9: Gri Commands
10: Programming
11: Environment
12: Emacs Mode
13: History
14: Installation
15: Gri Bugs
16: Test Suite
17: Gri in Press
18: Acknowledgments
19: License
Indices:
Concepts
Commands
Variables

### 10.9.6: Solitary Operators

Solitary operators do not act on items on the stack; rather, they generate items themselves and insert them on the stack.

The solitary operators are illustrated below, in alphabetical order.

`{rpn argc}`
  Yields number of command-line arguments given by the user when Gri was invoked. Thus, invoking Gri as

      gri myfile.gri file1.dat file2.dat

  yields 3, for arguments ``myfile.gri`', ``file1.dat`', and ``file2.dat`'. These arguments are accessible through the ``argv`' unary operator (see Unary Operators).

`{rpn e}`
  Yields the base of natural logarithms, i.e. ``2.718`'...

`{rpn pi}`
  Yields Pi, i.e. ``3.141`'...

`{rpn rand}`
  Generate a random number in the range 0 to 1, using the C subroutine ``drand48()`' if it is available, otherwise the less well-distributed ``rand()`' subroutine.

`{rpn wordc}`
  Returns number of words used in invoking the present command. Similar to the ``\.words.`' synonym (see Local Synonyms). Example:

      `let us test .it.'
      {
        show "This command has " {rpn wordc} " words"
      }
      let us test 10
      let us test {rpn 3 1 +}
      let us test "this"
      let us test "this thing"

  The operator ``wordv`' may be used to extract the words of the command (see Unary Operators).