Re^3: Speeding permutation counting

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Re^4: Speeding permutation counting by BrowserUk (Patriarch) on Jul 19, 2007 at 21:15 UTC
Oh. I see what you mean. Eg. If of 1000 strings, 500 have a 1 in bit 0, then you know that in the 500500 2-way compares, you would get '00' & '11' 1/4 of the time each and '01' or '10' 1/2 of the time. But I don't see a way of determining how many '10's relative to the '01's? And no way to determine which pairs of strings render which values for any given bit, nor a count of the four possible values for any given pair of strings? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply]
Re^5: Speeding permutation counting by Limbic~Region (Chancellor) on Jul 20, 2007 at 00:08 UTC
BrowserUk, I am likely misunderstanding the problem. For the sake of simplicity, I am using strings of 1 character. Do I have the correct output for the provided input? `string 1: 0 string 2: 1 string 3: 0 string 4: 1 string 5: 0 1 & 2 -> 01 10 1 & 3 -> 00 00 1 & 4 -> 01 10 1 & 5 -> 00 00 2 & 3 -> 10 01 2 & 4 -> 11 11 2 & 5 -> 10 01 3 & 4 -> 01 10 3 & 5 -> 00 00 4 & 5 -> 10 01 Totals 01 = 6 10 = 6 11 = 2 00 = 6` [download] If that is correct, then I think my math approach will work. Cheers - L~R	[reply] [d/l]
Re^6: Speeding permutation counting by BrowserUk (Patriarch) on Jul 20, 2007 at 00:19 UTC
What the OP is calculating is the number of bit pairing (4 values) for each combination of 2 strings. Eg: Assuming 32-bit strings, typical values might be: `strings: '00' '01' '10' '11' 1 & 2 10 5 12 15 1 & 3 2 17 7 6 1 & 4 1 & 5 2 & 3 ....` [download] So the OP wants 4 numbers per pairing of strings, regardless of the number of bits. What you would be calculating is 4 numbers per bit position, regardless of the number of strings. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l]
Re^7: Speeding permutation counting by Limbic~Region (Chancellor) on Jul 20, 2007 at 00:58 UTC


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