[#9722] Kernel#system broken inside Dir.chdir(&block) if system command doesn't have shell characters — <noreply@...>

Bugs item #7278, was opened at 2006-12-14 13:59

8 messages 2006/12/14

[#9749] System V IPC in standard library? — Steven Jenkins <steven.jenkins@...>

Back in August, I needed a semaphore to serialize access to an external

14 messages 2006/12/19

[#9753] CVS freeze — SASADA Koichi <ko1@...>

Hi,

20 messages 2006/12/20
[#9755] Re: [ruby-dev:30039] CVS freeze — SASADA Koichi <ko1@...> 2006/12/20

Hi,

[#9757] Re: [ruby-dev:30040] Re: CVS freeze — SASADA Koichi <ko1@...> 2006/12/20

Hi,

Re: [ ruby-Bugs-7001 ] Determinant Problem in Matrix.rb

From: Steven Jenkins <steven.jenkins@...>
Date: 2006-12-01 15:48:45 UTC
List: ruby-core #9649
Nex3 wrote:
> Given that the typical way of calculating determinants involves no
> division at all, it seems odd that I would be required to use floats to
> get the correct result. In addition, the documentation of the Matrix
> class doesn't say that one should use floats... in fact, the example
> given for Matrix#determinant is done with integers.

Just out of curiosity, are you trying to actually calculate something
useful with determinants? The determinant is a powerful theoretical
concept, but virtually useless computationally. That is, whatever you
can do using a determinant can likely be done faster and more accurately
using some other technique.

For example, solving a linear system using Cramer's rule is an order of
magnitude more work than Gaussian elimination.

Steve

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