problem.parseformula
problem.parseformula |
Purpose
Parse a formula written as an unparsed array of tokens into internal parsed (reverse Polish) format
Synopsis
ntoken = problem.parseformula (intype, invalue, type, value)
Arguments
|
intype
|
Array of token types providing the unparsed formula.
|
|
invalue
|
Array of values corresponding to the types in
inType.
|
|
ntoken
|
The number of tokens in the parsed formula (not counting the terminating
xslp_op_eof token).
|
|
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 with index
iX and
iY respectively, the following example converts the formula "sin(x+y)" into internal parsed format, and then writes it out as a sequence of tokens.
intype = []
invalue = []
intype = [xslp_op_ifun, xslp_op_lb, xslp_op_col, xslp_op_op,
xslp_op_col, xslp_op_rb, xslp_op_eof]
invalue = [xslp_op_sin, 0, iX , xslp_op_plus,
iY, 0, 0]
type = []
value = []
ntoken = p.parseformula (intype, invalue, type, value)
i=0
while type[n] != xslp_op_eof:
str = p.itemname (type[i], value[i])
print (str)
i += 1
Further information
For possible token types and values, see the chapter on "Formula Parsing" in the SLP reference manual.
Related topics