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Re: Series[log[x], {x, 0, 3}]

  • To: mathgroup at smc.vnet.net
  • Subject: [mg119269] Re: Series[log[x], {x, 0, 3}]
  • From: Helen Read <readhpr at gmail.com>
  • Date: Sat, 28 May 2011 07:18:46 -0400 (EDT)
  • References: <irntgd$soc$1@smc.vnet.net>

This is getting way off topic, but I don't generally have occasion to 
write such things, and I didn't say that I never use the circle 
notation, rather, *almost* never.

HPR

On 5/27/2011 6:13 AM, Murray Eisenberg wrote:
> Then how would you state in symbols the fact, say, that the standard
> matrix of the composite of two linear transformations is their matrix
> product? Or that the derivative of the composite f@g is (f'@g)*g' ?
> Do you always write such things either in words or symbolically but with
> explicit arguments?
>
> On 5/25/2011 7:31 PM, Helen Read wrote:
>> It's definitely a matter of taste. I almost never use the circle
>> notation for function composition, and I dislike the @ notation for
>> similar reasons.
>>
>> HPR
>>
>> On 5/25/2011 5:55 AM, Murray Eisenberg wrote:
>>> I agree that in many instances, using something of the form f@x may seem
>>> at odds with traditional mathematical notation. (Although it's still
>>> useful in avoiding the eye-nuisance of nested brackets in a construction
>>> such as g[f[x]].)
>>>
>>> But something of the form g@f[x] is very natural from the viewpoint of
>>> traditional mathematical notation: the "@" is reminiscent of the circle
>>> operator denoting functional composition.
>>>
>>> Usually, using @ seems to be a matter of either stressing a particular
>>> meaning or else making an expression easier to read. (Making an
>>> expression easier to type is hardly ever the reason I, at least, would
>>> use @.)
>>>
>>> On 5/24/2011 5:59 AM, Helen Read wrote:
>>>> On 5/23/2011 6:24 AM, Bill Rowe wrote:
>>>>> On 5/22/11 at 6:55 AM, hszhao.cn at gmail.com (Hongsheng Zhao) wrote:
>>>>>
>>>>> While I cannot speak for DrMajorBob, my reason for using the
>>>>> notation f@x rather than f[x] is primarily readability. Constrast
>>>>>
>>>>> Sqrt[Abs[Sin[x]]]
>>>>>
>>>>> with Sqrt[Abs@Sin@x]
>>>>>
>>>>> Both do the same, but for me, it is easier to see what the
>>>>> second form does than the first. Deeply nested brackets are more
>>>>> difficult for me to read. And there is the additional factor of
>>>>> less typing required for the second form.
>>>>
>>>> Each to his/her own. Personally I far prefer the nested brackets, which
>>>> to me is more readable -- it's closer to familiar written mathematical
>>>> notation, and it's clear where each function ends.
>>>>
>>>> And I don't see how the @ sign results in any less typing.
>>>>
>>>> @  requires pressing two keys simultaneously, Shift+2
>>>>
>>>> [ ] requires two keys (one at a time), the [ and ]
>>>> or two keys simultaneously Alt+]  to get matched brackets
>>>>
>>>>
>>>
>>
>>
>>
>>
>




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