# Logarithmic interval ?

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## Logarithmic interval ?

 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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## Re: Logarithmic interval ?

 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 <[hidden email]> 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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## Re: Logarithmic interval ?

 I used a workaround that probably is more flexible since I have several variables that need the logarithmsteps := 100.xLog := 0.02 log: steps.yLog := 1.894 log: steps1 to: steps do:[:i|              x := i raisedTo: xLog.          y := i raisedTo: yLog.          ]Best,KarlOn Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> 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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## Re: Logarithmic interval ?

 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 <[hidden email]> a écrit :I used a workaround that probably is more flexible since I have several variables that need the logarithmsteps := 100.xLog := 0.02 log: steps.yLog := 1.894 log: steps1 to: steps do:[:i|              x := i raisedTo: xLog.          y := i raisedTo: yLog.          ]Best,KarlOn Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> 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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## Re: Logarithmic interval ?

 You are right.It would be nice to have a logarithmic interval.Best.KarlOn Sun, Feb 3, 2019 at 6:37 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> a écrit :I used a workaround that probably is more flexible since I have several variables that need the logarithmsteps := 100.xLog := 0.02 log: steps.yLog := 1.894 log: steps1 to: steps do:[:i|              x := i raisedTo: xLog.          y := i raisedTo: yLog.          ]Best,KarlOn Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> 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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## Re: Logarithmic interval ?

 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 <[hidden email]> a écrit :You are right.It would be nice to have a logarithmic interval.Best.KarlOn Sun, Feb 3, 2019 at 6:37 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> a écrit :I used a workaround that probably is more flexible since I have several variables that need the logarithmsteps := 100.xLog := 0.02 log: steps.yLog := 1.894 log: steps1 to: steps do:[:i|              x := i raisedTo: xLog.          y := i raisedTo: yLog.          ]Best,KarlOn Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> 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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## Re: Logarithmic interval ?

 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 <[hidden email]> 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 <[hidden email]> a écrit :You are right.It would be nice to have a logarithmic interval.Best.KarlOn Sun, Feb 3, 2019 at 6:37 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> a écrit :I used a workaround that probably is more flexible since I have several variables that need the logarithmsteps := 100.xLog := 0.02 log: steps.yLog := 1.894 log: steps1 to: steps do:[:i|              x := i raisedTo: xLog.          y := i raisedTo: yLog.          ]Best,KarlOn Sun, Feb 3, 2019 at 5:10 PM Nicolas Cellier <[hidden email]> 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 <[hidden email]> 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