From jerry.lewis at biogen.com  Sat Feb 18 03:43:10 2017
From: jerry.lewis at biogen.com (Jerry Lewis)
Date: Sat, 18 Feb 2017 02:43:10 +0000
Subject: [Rd] Wish List: Extensions to the derivatives table
In-Reply-To: <4d84ab5a-7b52-6989-a001-ad147dedfb0b@gmail.com>
References: <SN1PR12MB03180780C156867FC3A0CB89815D0@SN1PR12MB0318.namprd12.prod.outlook.com>
	<4d84ab5a-7b52-6989-a001-ad147dedfb0b@gmail.com>
Message-ID: <SN1PR12MB0318605F1C83AFC41DAC7B3B815C0@SN1PR12MB0318.namprd12.prod.outlook.com>

Thank you.  The nlsr package will be a satisfactory alternative once the bug in fnDeriv(..., hessian=TRUE) is patched.  I have notified the maintainer.

Jerry

-----Original Message-----
From: Duncan Murdoch [mailto:murdoch.duncan at gmail.com] 
Sent: Friday, February 17, 2017 6:05 PM
To: Jerry Lewis; r-devel at r-project.org
Subject: Re: [Rd] Wish List: Extensions to the derivatives table

On 17/02/2017 1:59 PM, Jerry Lewis wrote:
> The derivative table resides in the function D.  In S+ that table is extensible because it is written in the S language.  R is faster but less flexible, since that table is programmed in C.  It would be useful if R provided a mechanism for extending the derivative table, or barring that, provided a broader table.  Currently unsupported mathematical functions of one argument include expm1, log1p, log2, log10, cospi, sinpi, and tanpi.
>
> While manual differentiation of these proposed additions is straight-forward, their absence complicates what otherwise could be much simpler, such as using deriv() or deriv3() to generate functions, for example to use as an nls model.

The nlsr package allows you to specify derivatives.

Duncan Murdoch



[Rd] Wish List: Extensions to the derivatives table
Jerry Lewis