From: mail@...
Date: 2014-10-18T04:31:06+00:00
Subject: [ruby-core:65777] [ruby-trunk - Feature #10225] [PATCH] *math.c: New method Math.normcdf

Issue #10225 has been updated by gogo tanaka.


@David MacMahon 

 Thank you for your valuable comment.

I definitely agree with you. I really want 'built-in way of dealing with multidimensional numerical arrays'

Right now we have `Matrix` class as standard lib,(it's good!) but it has a problem with performance. (It makes object for each lattice.)
On the other hand  SciRuby provide nice gem `NMatrix`, but we can face some troublesome when installing and updating.(It need ATLAS with CBLAS) 

(NumPy does not require any external linear algebra, I like it)

So I have longed for such a built-in way of dealing with multidimensional numerical arrays better.

----------------------------------------
Feature #10225: [PATCH] *math.c: New method Math.normcdf 
https://bugs.ruby-lang.org/issues/10225#change-49513

* Author: gogo tanaka
* Status: Open
* Priority: Normal
* Assignee: 
* Category: math
* Target version: current: 2.2.0
----------------------------------------
I know it looks kind of arbitrary or unnecessary feature ,but I believe that

to provide such a feature as official is helpful to make people we couldn't reach so far have interest in Ruby.

(Actually only this feature is not enough to do that..)

By the way I still wonder whether naming method make sense.

Debating between ...

```
Math::pnorm   -> R language use this
Math::phi     -> Euler's totient function is more popular as phi,
Math::ncdf
Math::guesscdf
Math::cdf_of_norm,
Math::cdf_of_guess
```

Finally I come to the conclusion Math::normcdf is most proper length, meaning and has no other worries.

---Files--------------------------------
_ math.c New method Math.normcdf.PATCH (1.04 KB)
_ test_math.rb Add tests for Math.normcdf.PATCH (609 Bytes)
_ NEWS About Math.normcdf.PATCH (488 Bytes)


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