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problem.parsecformula

problem.parsecformula


Purpose
Parse a formula written as a character string into internal parsed (reverse Polish) format
Synopsis
ntoken = problem.parsecformula (formula, type, value)
Arguments
ntoken 
Number of tokens in the parsed formula (not counting the terminating xslp_op_eof token).
formula 
Character string containing the formula, written in the same free-format style as used in formulae in Extended MPS format, with spaces separating tokens.
Type 
Array of token types providing the parsed formula.
Value 
Array of values corresponding to the types in Type.
Example
Assuming that x and y are already defined as columns, the following example converts the formula "sin(x+y)" into internal parsed format, and then writes it out as a sequence of tokens.
type  = []
value = []
ntoken = p.parsecformula ("sin ( x + y )", Type, Value)
i = 0
while type[i] != xslp_op_eof:
  str = p.itemname (type[i], value[i])
  printf (str)
  i += 1
Further information

Tokens are identified by name, so any columns or user functions which appear in the formula must already have been defined. Unidentified tokens will appear as type xslp_UNKNOWN.


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