Re: Permutations to scalars and back again.

2016-09-19 Thread Peter Fairbrother
On 19/09/16 02:45, James A. Donald wrote: On 9/12/2016 8:01 PM, Georgi Guninski wrote: On Mon, Sep 12, 2016 at 07:50:50PM +1000, James A. Donald wrote: To restate the problem: Find a mapping between integers and injective functions from N to X up to a permutation of N. In this case, find a ma

Re: Permutations to scalars and back again.

2016-09-18 Thread James A. Donald
On 9/12/2016 8:01 PM, Georgi Guninski wrote: On Mon, Sep 12, 2016 at 07:50:50PM +1000, James A. Donald wrote: To restate the problem: Find a mapping between integers and injective functions from N to X up to a permutation of N. In this case, find a mapping between integers and an injective fun

Re: Permutations to scalars and back again.

2016-09-13 Thread Peter Fairbrother
On 12/09/16 11:24, Peter Fairbrother wrote: On 12/09/16 02:09, James A. Donald wrote: I need to be able to do two of the following three tasks. Generate a permutation of eighteen ones and eighteen zeros with equal probability for each permutation. Or equivalently shuffle eighteen black cards a

Re: Permutations to scalars and back again.

2016-09-12 Thread Peter Fairbrother
On 12/09/16 11:24, Peter Fairbrother wrote: On 12/09/16 02:09, James A. Donald wrote: I need to be able to do two of the following three tasks. Generate a permutation of eighteen ones and eighteen zeros with equal probability for each permutation. Or equivalently shuffle eighteen black cards a

Re: Permutations to scalars and back again.

2016-09-12 Thread Peter Fairbrother
On 12/09/16 02:09, James A. Donald wrote: I need to be able to do two of the following three tasks. Generate a permutation of eighteen ones and eighteen zeros with equal probability for each permutation. Or equivalently shuffle eighteen black cards and eighteen red cards. Sequentially generate

Re: Permutations to scalars and back again.

2016-09-12 Thread Georgi Guninski
On Mon, Sep 12, 2016 at 07:50:50PM +1000, James A. Donald wrote: > To restate the problem: Find a mapping between integers and injective > functions from N to X up to a permutation of N. > > In this case, find a mapping between integers and an injective functions > from 18 to 36. Sage (open sour

Re: Permutations to scalars and back again.

2016-09-12 Thread James A. Donald
To restate the problem: Find a mapping between integers and injective functions from N to X up to a permutation of N. In this case, find a mapping between integers and an injective functions from 18 to 36.

Re: Permutations to scalars and back again.

2016-09-12 Thread James A. Donald
On 9/12/2016 12:09 PM, Mark Steward wrote: And the wikipedia page https://en.wikipedia.org/wiki/Combinatorial_number_system. Again, unique and distinct elements. My problem is interchangeable elements.

Re: Permutations to scalars and back again.

2016-09-12 Thread James A. Donald
On 9/12/2016 11:52 AM, stef wrote: On Mon, Sep 12, 2016 at 11:09:06AM +1000, James A. Donald wrote: I need to be able to do two of the following three tasks. Generate a permutation of eighteen ones and eighteen zeros with equal probability for each permutation. Or equivalently shuffle eighteen

Re: Permutations to scalars and back again.

2016-09-11 Thread jim bell
osely related to those of an LFSR."[end of quote]            Jim Bell × From: James A. Donald To: cypherpunks@lists.cpunks.org Sent: Sunday, September 11, 2016 6:09 PM Subject: Permutations to scalars and back again. I need to be able to do two of the following three tasks.

Re: Permutations to scalars and back again.

2016-09-11 Thread Mark Steward
And the wikipedia page https://en.wikipedia.org/wiki/Combinatorial_number_system. If you want some more theoretical stuff, Knuth has a chapter about combinations that's easily googleable. Mark On 12 Sep 2016 03:01, "stef" wrote: > On Mon, Sep 12, 2016 at 11:09:06AM +1000, James A. Donald wrote

Re: Permutations to scalars and back again.

2016-09-11 Thread stef
On Mon, Sep 12, 2016 at 11:09:06AM +1000, James A. Donald wrote: > I need to be able to do two of the following three tasks. > > Generate a permutation of eighteen ones and eighteen zeros with equal > probability for each permutation. Or equivalently shuffle eighteen black > cards and eighteen re

Permutations to scalars and back again.

2016-09-11 Thread James A. Donald
I need to be able to do two of the following three tasks. Generate a permutation of eighteen ones and eighteen zeros with equal probability for each permutation. Or equivalently shuffle eighteen black cards and eighteen red cards. Sequentially generate all possible permutations with each per