Re: Can Mathematica invert large complex arrays ( 700x700)?---in a timely way that is
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: Can Mathematica invert large complex arrays ( 700x700)?---in a timely way that is
- From: mek at guinan.psu.edu (Mark E. Kotanchek)
- Date: Fri, 15 May 92 09:27:18 EDT
Since David Jacobson did all the work of determining a function to
answer this question:
Gregory Lampshire asks about the time required to invert a
700x700 array in Mathematica.
I just did the following on an HP 9000/877 (snakes processor).
In[13]:=
Timing[Inverse[Table[Random[],{700},{700}]]]//First
Out[13]= 315.05 Second
The Timing command returns a list consisting of the time and the
answer. First grabs the time and throws away the answer, since I
didn't want my screen cluttered with 490000 numbers.
I did this after a whole day of working with mathematica. It
pushed the virtual memory consumption up to 50144K. I'm not
sure how much I had consumed up to the point where I did this
example, but it probably wasn't over 15 MB.
I plugged in David's function and ran it on my NeXTstation
(monochrome, 32 MB RAM) and came out with a result of:
532.867 Second
I noticed a reasonable amount of disk access during this processing.
I ran the command a second time with Mathematica as "first responder"
and "warmed up" and got a result of
520. Second
So, for what it's worth, enjoy.
Later,
Mark.
---
Mark Kotanchek
Guidance & Control Dept - 363 ASB
Applied Research Lab/Penn State
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e-mail: mek at guinan.psu.edu (NeXTmail)
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