Subject: re : cplex
i agree . i ( or chonawee ) will go ahead and place the order for cplex . i think
that this will provide us with a great set of tools .
- samer
pinnamaneni krishnarao @ ect
05 / 24 / 00 01 : 34 pm
to : samer takriti / enron communications @ enron communications @ enron , tom
halliburton / corp / enron @ enron
cc : grant masson / hou / ect @ ect , stinson gibner / hou / ect @ ect , chonawee
supatgiat / corp / enron @ enron , vince j kaminski / hou / ect @ ect
subject : re : cplex
i talked to vince about the optimization software issue . vince said that if
there are technical reasons for having two different packages and the
benefits outweigh the costs of maintaining two licenses , we can go ahead and
buy both . in my view , it is a great advantage to have both , as each has its
own strengths relative to the other . we have spent some time trying to come
up with one package that solves all of our problmes without success . there is
no point is wasting more time on this effort . let ' s go ahead and purchase
both .
krishna .
from : samer takriti @ enron communications on 05 / 24 / 2000 10 : 22 am
to : tom halliburton / corp / enron @ enron
cc : grant masson / hou / ect @ ect , pinnamaneni krishnarao / hou / ect @ ect , stinson
gibner / hou / ect @ ect , chonawee supatgiat / corp / enron @ enron
subject : re : cplex
tom ,
vince prefers to have one software package ( if possible ) . it is my
understanding that special ordered sets are recognized automatically
( internally ) by cplex . this seems to be the case for both cplex and osl
according to ampl ' s web page and other references ( check
lorderedsetsfeature ) . as a result , the cplex people feel that there is no
need to provide the user with the tools to represent special - ordered sets in
opl . as a matter of fact , the incapability of xpress to recognize them
automatically concerns me .
if you have special requirements , c code may be used to pass the information
to the solver ( which is straight forward ; all of chonawee ' s testing was done
this way ) . chonawee ' s benchmark shows a superior performance by cplex ( which
you indicated yourself in an earlier message ) .
if you feel that xpress is the only way to go , then feel free to purchase it
( the purchase order is on hold for the time being ) . however , we need to check
with vince first . i strongly feel that we should have one solver in order to
minimize cost and contractual headaches .
let us try to get this issue resolved by this afternoon . thanks .
- samer