#1199 mnewton does not work

closed
nobody
5
2007-07-18
2007-05-25
Anonymous
No

Maxima 5.12.0 http://maxima.sourceforge.net
Using Lisp CLISP 2.39 (2006-07-16)
...

The example for usage of mnewton from the manual
returns:
(%i2) mnewton([x1+3*log(x1)-x2^2, 2*x1^2-x1*x2-5*x1+1], [x1, x2], [5, 5]);
(%o2) [[x1 = 3.822890025575447, x2 = 2.807544757033248]]
instead of
[[x1 = 3.756834008012769, x2 = 2.779849592817897]],
as given in the manual.

Another example is:
(%i9) mnewton([2*(x1-1.1234),3*(x2-2.2345)], [x1, x2], [1,2]);
(%o9) [[x1 = 1.0, x2 = 2.166666666666667]]
and probably not what one expects.

Discussion

  • Robert Dodier
    Robert Dodier
    2007-07-03

    • labels: 460522 --> Share Libraries
     
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    Fixed in cvs by replacing the call to linsolve with linsolve_by_lu.

    In current cvs:

    (%i1) load(mnewton)$
    (%i2) mnewton([x1+3*log(x1)-x2^2, 2*x1^2-x1*x2-5*x1+1], [x1, x2], [5, 5]);
    (%o2) [[x1=3.7568340080128,x2=2.7798495928179]]
    (%i3) mnewton([2*(x1-1.1234),3*(x2-2.2345)], [x1, x2], [1,2]);
    (%o3) [[x1=1.1234,x2=2.2345]]

    Andrej

     
    • status: open --> closed