[R] A "rude" question

[Mulholland, Tom]

What makes you trust any software? 

There are some obvious points. First of all the code is open so if you know enough you can actually read the code and make sure it does what you want. Secondly you can replicate a process using two pieces of software and compare the results. You can check the archives and you will find a number of posts that talk about the results produced by R and how they compare with other software. Typically R versus Excel or R versus SPSS / SAS. Just be careful as different answers does not automatically mean one is wrong, and it certainly doesn't mean R is wrong.

Excel computes =ROUND(2.5,0) to be 3
R computes round(2.5) to be 2

As I understand it both are right, they are just using different standards. I however have always used the latter and rounded to the even number where the figure to be rounded lies exactly at the halfway mark.

Hang around this list for a short time and it will become evident that if this software didn't work; the people using it would have stopped using it long ago.

Forget the commercial versus open software arguments that raise their head from time to time. The question is how well a piece of software is written / maintained & supported and not issues of payment or the greater good. There is some woeful  freeware, just as there is some woeful commercial products.

The pedigree of the contributors to the base package is hard to beat. I wouldn't know the pedigree of those who write the other stats programmes, but I assume that R contributors are right in there, with the best.

As to packages. They must vary with quality, and people do make mistakes. If you have something that in modern parlance is "mission critical" it wouldn't matter which product you had, you would test it to see that it fitted your requirements.

You have raised a question that is often ignored or assumed. But to really know the answer for yourself you need to test it yourself or rely upon others that you trust. Whenever I start using a package I make sure it does not just what it states it can do, but also that it does what I want it to do.

Tom


> -----Original Message-----
> From: msck9 at mizzou.edu [mailto:msck9 at mizzou.edu]
> Sent: Thursday, 27 January 2005 1:10 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] A "rude" question
> 
> 
> Dear all, 
>  I am beginner using R. I have a question about it. When you use it,
>  since it is written by so many authors, how do you know that the
>  results are trustable?(I don't want to affend anyone, also I trust
>  people). But I think this should be a question.
> 
>  Thanks,
>  Ming
> 
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