XSLPpreparseformula
XSLPpreparseformula |
Purpose
Perform an initial scan of a formula written as a character string, identifying the operators but not attempting to identify the types of the individual tokens
Synopsis
int XPRS_CC XSLPpreparseformula(XSLPprob Prob, char *Formula, int *nToken, int *Type, double *Value, char *StringTable, int *SizeTable);
Arguments
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Prob
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The current SLP problem.
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Formula
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Character string containing the formula, written in the same free-format style as formulae in Extended MPS format, with spaces separating tokens.
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nToken
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Address of an integer to receive the number of tokens in the parsed formula (not counting the terminating
XSLP_EOF token). May be
NULL if not required.
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Type
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Array of token types providing the parsed formula.
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Value
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Array of values corresponding to the types in
Type.
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StringTable
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Character buffer to receive the names of the unidentified tokens.
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SizeTable
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Address of an integer variable to hold the size of
StringTable actually used. May be
NULL if not required.
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Example
The following example converts the formula "sin(x+y)" into internal parsed format without trying to identify the tokens apart from operands and numbers, and then writes it out as a sequence of tokens.
int n, Type[20];
double Value[20];
char Strings[200];
XSLPpreparseformula(Prob, "sin ( x + y )", NULL,
Type, Value, Strings, NULL);
printf("\n");
for (n=0;Type[n] != XSLP_EOF;n++) {
if (Type[n] == XSLP_UNKNOWN)
printf("\n? %s",Strings[(int)Value[n]]);
else {
XSLPitemname(Prob, Type[n], Value[n], Buffer);
printf(" %s", Buffer);
}
}
Further information
Only operands and numbers are identified by XSLPpreparseformula. All other operands, including names of variables, functions are left as strings of type XSLP_UNKNOWN. The Value of such a type is the index in StringTable of the start of the token name.
The parsed formula can be converted into a calculable formula by replacing the XSLP_UNKNOWN tokens by the correct types and values.
Related topics