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The Novalue Type In O-Matrix
Syntax novalue
See Also: type

Description
The novalue function returns a matrix with type equal to "novalue". You can pass these matrices as arguments and you can check their type.

Example
This function can be used to define a variable before the value of the variable is known. (It is preferable to set such a variable to novalue rather than 0 so that an error will occur if the value is used.) If you enter
     function f(x) begin
          print type(x)
          x = 5
     end
     f(y)
O-Matrix will attempt to find a file named Y.OMS and if it cannot it will respond with an error message saying that y is not defined. If you continue by entering
     y = novalue
     f(y)
     print y
O-Matrix will respond
     novalue
     5