## [squeak-dev] Logarithmic interval ?

karl ramberg karlramberg at gmail.com
Sat Feb 9 16:04:54 UTC 2019

```Hi,
Cool. I will try it soon. I have a cold at the moment :-(

Cheers,
Karl

On Fri, Feb 8, 2019 at 10:28 PM Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> wrote:

> 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: ''
>>
>> 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
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>
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