forcing numerical evaluation-- answer -- (thanks Barton)



With such a huge expression, there is the possibility of 
large subtractive cancellation errors. I suggest that you 
use bfloats with varying values for fpprec -- this 
will give you some confidence that your answer accurate.
Try something like

for i : 20 thru 40 do (
       fpprec : i,
       print(expand(fullmap('bfloat,q))));


Barton




steve@horne.homelinux.net
Sent by: maxima-admin@math.utexas.edu
10/28/2003 04:20 PM

 
        To:     Maxima@www.ma.utexas.edu
        cc: 
        Subject:        [Maxima] forcing numerical evaluation-- answer -- (thanks Barton)




 string(q1);

(D1121) 
-((8*%E^(%E/(%E-1)+1/(%E-1)+3)-12*%E^(%E/(%E-1)+1/(%E-1)+2)+6*%E^(%E/(#

%E-1)+1/(%E-1)+1)-%E^(%E/(%E-1)+1/(%E-1)))*t^2+(%E*(34*%E^(%E/(%E-1)+1/(%E-1))#

-44*%E^(2*%E/(%E-1))-6*%E^(2/(%E-1)))+%E^3*(8*%E^(%E/(%E-1)+1/(%E-1))-16*%E^(2#
....



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