[squeak-dev] Logarithmic interval ?

Nicolas Cellier nicolas.cellier.aka.nice at gmail.com
Fri Feb 8 21:27:53 UTC 2019


And I have added a LogarithmicInterval which is more like numpy.logspace.

For a LogarithmicInterval, bounds are specified by their logarithm (in
whatever base).

If you want 100 points from 0.1 to: 10.0, then you can write:
    (0.1 log logTo: 10 log size: 100 base: 10).
or:
    (-1 logTo: 1 size: 100 base: 10)
or you can omit the base and use ln/exp
    (0.1 ln logTo: 10 ln size: 100).

Le ven. 8 févr. 2019 à 15:56, Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> a écrit :

> Hi Karl, I published GeometricInterval along with some
> GeometricIntervalTests at
>
>     MCHttpRepository
>         location: 'http://www.squeaksource.com/STEM'
>         user: ''
>         password: ''.
>
> It is a port of VW SYSEXT-GeometricInterval from Cincom public store, a
> bit revisited.
>
> Le dim. 3 févr. 2019 à 21:18, karl ramberg <karlramberg at gmail.com> a
> écrit :
>
>> You are right.
>> It would be nice to have a logarithmic interval.
>>
>> Best.
>> Karl
>>
>>
>> On Sun, Feb 3, 2019 at 6:37 PM Nicolas Cellier <
>> nicolas.cellier.aka.nice at gmail.com> wrote:
>>
>>> Hi karl,
>>> This is not a logarithmic interval. The progression should be geometric,
>>> that is with a constant ratio.
>>>
>>>     x3/x2 = (x2/x1).
>>>
>>> The ith element of geometric serie should be something like
>>>
>>>     (ratio raisedTo: i-1) * start.
>>>
>>> Le dim. 3 févr. 2019 à 18:15, karl ramberg <karlramberg at gmail.com> a
>>> écrit :
>>>
>>>> I used a workaround that probably is more flexible since I have several
>>>> variables that need the logarithm
>>>>
>>>> steps := 100.
>>>> xLog := 0.02 log: steps.
>>>> yLog := 1.894 log: steps
>>>> 1 to: steps do:[:i|
>>>>           x := i raisedTo: xLog.
>>>>           y := i raisedTo: yLog.
>>>>           ]
>>>>
>>>> Best,
>>>> Karl
>>>>
>>>>
>>>>
>>>> On Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <
>>>> nicolas.cellier.aka.nice at gmail.com> wrote:
>>>>
>>>>> Yes,
>>>>> But i don't remember if published somewhere... I'll check this evening
>>>>> or tomorrow
>>>>>
>>>>> Le dim. 3 févr. 2019 à 16:43, karl ramberg <karlramberg at gmail.com> a
>>>>> écrit :
>>>>>
>>>>>> Hi,
>>>>>> Does anybody know of a logarithmic interval implementation in Squeak
>>>>>> where the steps in the interval go by logarithmic scale instead of linear ?
>>>>>>
>>>>>> Best,
>>>>>> Karl
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20190208/4d838b38/attachment.html>


More information about the Squeak-dev mailing list