A little problem with negative exponentiation

GAMS
1

Hello:

I have a little confusion, in the model that I’m developing there is a
constraint that has terms like this:

(Log10(R)*)*n, (Log10(S))**m

the problem is R and S are continuous variables between 1 & 0, and
with Log10 (R) or Log10(S), gives a negative number , and n,m are real
and positive numbers, hence the solver gives me the following error:

**** Exec Error at line 690: rPower: FUNC DOMAIN: x**y, x < 0

is there a way to include exponentitation of negative numbers??

thanks,
best regards

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2

Daniel, the real power is not defined for a negative base (e.g.
http://www.cppreference.com/stdmath/pow.html). iI your n and m are
integers, you could use integer power:

GAMS Syntax: power(Log10(R),n) and power(Log10(S),m).

Michael Bussieck, GAMSWorld Coordinator

On Jul 24, 4:46 pm, Daniel wrote:

Hello:

I have a little confusion, in the model that I’m developing there is a
constraint that has terms like this:

(Log10(R)*)*n, (Log10(S))**m

the problem is R and S are continuous variables between 1 & 0, and
with Log10 (R) or Log10(S), gives a negative number , and n,m are real
and positive numbers, hence the solver gives me the following error:

**** Exec Error at line 690: rPower: FUNC DOMAIN: x**y, x >
is there a way to include exponentitation of negative numbers??

thanks,
best regards
–~–~---------~–~----~------------~-------~–~----~
To post to this group, send email to gamsworld@googlegroups.com
To unsubscribe from this group, send email to gamsworld-unsubscribe@googlegroups.com
For more options, visit this group at http://groups.google.com/group/gamsworld?hl=en
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