       Re: Determinant function in Mathematica

• To: mathgroup at yoda.physics.unc.edu
• Subject: Re: Determinant function in Mathematica
• From: "Lawrence M. Seiford, IEOR, UMass, 413/545-1658." <SEIFORD at ecs.umass.edu>
• Date: Mon, 13 Apr 1992 18:06 -0500

```    jpw at vax135.att.com writes:
>i repeated the exact code from Oliver Gloor (gloor at inf.ethz.ch) on
>Mathematica 1.2 under ULTRIX (3.x) running on a microVAX III (~3-4 MVUPs)
>and got the following timings (16 MB of real memory, 64 MB of swap)
>the timing difference are better than an order of magnitude faster on
>the microVAX versus the SPARC (which i find somewhat puzzling ...)

The difference isn't due to the machine but rather the version of Mathematica
used. As shown below--1.2 is considerably faster than 2.0!...larry

Mathematica (DEC RISC) 1.2 (January 24, 1990) [With pre-loaded data]
by S. Wolfram, D. Grayson, R. Maeder, H. Cejtin,
S. Omohundro, D. Ballman and J. Keiper
with I. Rivin and D. Withoff
-- Terminal graphics initialized --

In:= a[n_] := Table[ StringJoin["a",ToString[i],ToString[j]], {i,1,n}
,{j,1,n}];

In:= Do[ Print[ First[ Timing[ Det[ a[t]]]]], {t,1,7}]
0.
0.0166667 Second
0.0166667 Second
0.0666667 Second
0.216667 Second
1.25 Second
9.78333 Second

In:= Quit

Mathematica 2.0 for DEC RISC
Cannot connect to license server.  Retrying.
-- Terminal graphics initialized --

In:= a[n_] := Table[ StringJoin["a",ToString[i],ToString[j]], {i,1,n}
,{j,1,n}];

In:= Do[ Print[ First[ Timing[ Det[ a[t]]]]], {t,1,7}]
0.0166667 Second
0.0666667 Second
0.266667 Second
1. Second
5.76667 Second
70.65 Second

Interrupt> a

[Sorry, I couldn't afford the 45 minutes!]

```

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