Problem with MatrixPower, v. 2.1
- To: mathgroup at yoda.physics.unc.edu
- Subject: Problem with MatrixPower, v. 2.1
- From: "Katherine (Williams) Derbyshire" <kewms at kew.com>
- Date: Wed, 16 Dec 1992 18:52:54 EST
Page 659 of the Mathematica Book, second edition, gives an example of
the use of MatrixPower and MatrixExp:
m= {{0.4, 0.6}, {0.525, 0.475}}
MatrixPower[m,3]
{{0.465625, 0.534375}, {0.467578, {0.532422}}
Using the same matrix on my system (386/7 combination), I get very
different results from the example:
m = {{.4, .4}, {.525, .475}}
{{0.4, 0.4}, {0.525, 0.475}}
MatrixPower[m,3]
{{0.33175, 0.31425}, {0.412453, 0.390672}}
m.m.m
{{0.33175, 0.31425}, {0.412453, 0.390672}}
Yet Mathematica reports this result as accurate to 16 digits.
MatrixExp likewise gives a different result:
MatrixExp[m]
{{1.6553, 0.641593}, {0.842091, 1.7756}}
Why the discrepancy? Is the manual wrong? Is my system wrong?
What's up here?
--
Katherine (Williams) Derbyshire
kewms at kew.com
Riches are for spending. - Francis Bacon