[Pharo-project] Permutations and Combinations in SequenceableCollection
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of the entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package. -- -JT
On Jan 5, 2010, at 5:19 32PM, John Toohey wrote:
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of the entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package.
-- -JT
How about: #(1 2 3 4) combinations: 2 atATimeDo: [:array | array permutationsDo: [:each | Transcript show: each printString; cr]] ? Cheers, Henry
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences. On Tue, Jan 5, 2010 at 12:16, Henrik Johansen <henrik.s.johansen@veloxit.no>wrote:
On Jan 5, 2010, at 5:19 32PM, John Toohey wrote:
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of the entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package.
-- -JT
How about: #(1 2 3 4) combinations: 2 atATimeDo: [:array | array permutationsDo: [:each | Transcript show: each printString; cr]] ?
Cheers, Henry
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-- -JT
Can you give an example (on #(1 2 3 4) for instance) ? Thx 2010/1/5 John Toohey <jt@parspro.com>
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
On Tue, Jan 5, 2010 at 12:16, Henrik Johansen < henrik.s.johansen@veloxit.no> wrote:
On Jan 5, 2010, at 5:19 32PM, John Toohey wrote:
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of the entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package.
-- -JT
How about: #(1 2 3 4) combinations: 2 atATimeDo: [:array | array permutationsDo: [:each | Transcript show: each printString; cr]] ?
Cheers, Henry
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-- -JT
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-- Cédrick
On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
I guess you are looking for this: allPairsFromCollectionDo := [ :collection :block | | o | o := OrderedCollection newFrom: collection. o size timesRepeat: [ o with: collection do: block. o add: o removeFirst ] ]. Transcript open. allPairsFromCollectionDo value: #(1 2 3 4) value: [ :a :b | Transcript print: { a. b }; cr ]. Transcript flush Levente
On Tue, Jan 5, 2010 at 12:16, Henrik Johansen <henrik.s.johansen@veloxit.no>wrote:
On Jan 5, 2010, at 5:19 32PM, John Toohey wrote:
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of the entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package.
-- -JT
How about: #(1 2 3 4) combinations: 2 atATimeDo: [:array | array permutationsDo: [:each | Transcript show: each printString; cr]] ?
Cheers, Henry
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-- -JT
Very nice, thank you. On Tue, Jan 5, 2010 at 17:21, Levente Uzonyi <leves@elte.hu> wrote:
On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
I guess you are looking for this: allPairsFromCollectionDo := [ :collection :block | | o | o := OrderedCollection newFrom: collection. o size timesRepeat: [ o with: collection do: block. o add: o removeFirst ] ].
Transcript open. allPairsFromCollectionDo value: #(1 2 3 4) value: [ :a :b | Transcript print: { a. b }; cr ]. Transcript flush
Levente
On Tue, Jan 5, 2010 at 12:16, Henrik Johansen <henrik.s.johansen@veloxit.no>wrote:
On Jan 5, 2010, at 5:19 32PM, John Toohey wrote:
Hi, I'm trying to generate the permutations of a sequence of numbers. I've found # permutationsDo: aBlock, but this generated the permutation of
the
entire sequence. I want to do it in groups of 2. The #combinations: anInteger atATimeDo: aBlock method does what I need for combinations, but I cannot find the equivalent for permutations. Does something like this exist in the standard library, or in an external package.
-- -JT
How about: #(1 2 3 4) combinations: 2 atATimeDo: [:array | array permutationsDo: [:each | Transcript show: each printString; cr]] ?
Cheers, Henry
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-- -JT
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-- -JT
"Levente" == Levente Uzonyi <leves@elte.hu> writes:
Levente> On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
Levente> I guess you are looking for this: Levente> allPairsFromCollectionDo := [ :collection :block | Levente> | o | Levente> o := OrderedCollection newFrom: collection. Levente> o size timesRepeat: [ Levente> o with: collection do: block. Levente> o add: o removeFirst ] ]. Or more simply: aCollection do: [:x | aCollection do: [:y | "use x and y"]]. Unless I'm misunderstanding the problem. Which is neither combinations nor permutations, but so far is the only thing that fits all the bizarre conditions. -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
What I needed to do was from a sequence of say, 0 to: 4, produce #(0 0)#(1 1)#(2 2)#(3 3)#(4 4)#(1 0)#(2 1)#(3 2)#(4 3)#(0 4)#(2 0)#(3 1)#(4 2)#(0 3)#(1 4)#(3 0)#(4 1)#(0 2)#(1 3)#(2 4)#(4 0)#(0 1)#(1 2)#(2 3)#(3 4). Basically, I wanted to generate all possible scores for a soccer match, hence the 1-1, 0-0, etc. On Tue, Jan 5, 2010 at 19:58, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"Levente" == Levente Uzonyi <leves@elte.hu> writes:
Levente> On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
Levente> I guess you are looking for this: Levente> allPairsFromCollectionDo := [ :collection :block | Levente> | o | Levente> o := OrderedCollection newFrom: collection. Levente> o size timesRepeat: [ Levente> o with: collection do: block. Levente> o add: o removeFirst ] ].
Or more simply:
aCollection do: [:x | aCollection do: [:y | "use x and y"]].
Unless I'm misunderstanding the problem.
Which is neither combinations nor permutations, but so far is the only thing that fits all the bizarre conditions.
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
"John" == John Toohey <jt@parspro.com> writes:
John> What I needed to do was from a sequence of say, 0 to: 4, produce #(0 0)#(1 John> 1)#(2 2)#(3 3)#(4 4)#(1 0)#(2 1)#(3 2)#(4 3)#(0 4)#(2 0)#(3 1)#(4 2)#(0 John> 3)#(1 4)#(3 0)#(4 1)#(0 2)#(1 3)#(2 4)#(4 0)#(0 1)#(1 2)#(2 3)#(3 John> 4). Basically, I wanted to generate all possible scores for a soccer match, John> hence the 1-1, 0-0, etc. That's what I did. You want X, Y for all possible values of X from 0 to 4 and Y from 0 to 4, right? That's *not* permutations. That's *not* combinations. That's "combinations with replacement/repetition". ... http://en.wikipedia.org/wiki/Combination I hate it when people use the words permutation or combination without realizing they have specific math meanings. But that's not your fault, but I hope you never do it again. :) -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
Thank you, duly chastened. I did know the formulae for P and C, but didn't know how to add the repetitions. My original code was :- |c| c := SortedCollection new. c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c add:( each reverse) asCommaString]. ^c Really glad that I asked the question. Thank you again. On Tue, Jan 5, 2010 at 20:36, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> What I needed to do was from a sequence of say, 0 to: 4, produce #(0 0)#(1 John> 1)#(2 2)#(3 3)#(4 4)#(1 0)#(2 1)#(3 2)#(4 3)#(0 4)#(2 0)#(3 1)#(4 2)#(0 John> 3)#(1 4)#(3 0)#(4 1)#(0 2)#(1 3)#(2 4)#(4 0)#(0 1)#(1 2)#(2 3)#(3 John> 4). Basically, I wanted to generate all possible scores for a soccer match, John> hence the 1-1, 0-0, etc.
That's what I did.
You want X, Y for all possible values of X from 0 to 4 and Y from 0 to 4, right?
That's *not* permutations.
That's *not* combinations.
That's "combinations with replacement/repetition".
... http://en.wikipedia.org/wiki/Combination
I hate it when people use the words permutation or combination without realizing they have specific math meanings. But that's not your fault, but I hope you never do it again. :)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString]. "Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!" "why don't you just use the laser cutter? no losses!" :-) -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
:-) I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points. On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
I guess its just something like this :- |c| c := #(1 2 3 6 7 2 4 6 12 14 3 6 9 18 21 4 8 12 24 28 5 10 15 32 35). c do: [:x | c do: [:y | Transcript show: '('; show: x; show: '-'; show: y;show:')']]. On Tue, Jan 5, 2010 at 21:34, John Toohey <jt@parspro.com> wrote:
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
-- -JT
2010/1/5 John Toohey <jt@parspro.com>
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
Since the increments include 1 this is equivalent to (0 to: max) allPairsDo: ... i.e. it is possible for a team to continue to score a single point, therefore the possible pairs of scores are all the pairs from 0 to N. But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
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Yep, the four scores would be 1 point conversion, 2 point conversion or a safety, 3 point field goal, and a 6 point touchdown. Although the 1 point can only come after a 6 point touchdown, so any score with just a 1 point would not be possible, but in theory, you could have 2-2, 4-4 etc. 2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
Since the increments include 1 this is equivalent to (0 to: max) allPairsDo: ... i.e. it is possible for a team to continue to score a single point, therefore the possible pairs of scores are all the pairs from 0 to N.
But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
-- -JT
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-- -JT
2010/1/5 John Toohey <jt@parspro.com>
Yep, the four scores would be 1 point conversion, 2 point conversion or a safety, 3 point field goal, and a 6 point touchdown. Although the 1 point can only come after a 6 point touchdown, so any score with just a 1 point would not be possible, but in theory, you could have 2-2, 4-4 etc.
So that has to be #(0), (2 to: limit) allPairsDo: right? Since 2 is the lowest score, 3 the next, 4 = 2 + 2, 5 = 3 + 2, right?
2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
Since the increments include 1 this is equivalent to (0 to: max) allPairsDo: ... i.e. it is possible for a team to continue to score a single point, therefore the possible pairs of scores are all the pairs from 0 to N.
But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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-- -JT
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Yes, I think that would do it. What class is #allPairsDo: defined? 2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
Yep, the four scores would be 1 point conversion, 2 point conversion or a safety, 3 point field goal, and a 6 point touchdown. Although the 1 point can only come after a 6 point touchdown, so any score with just a 1 point would not be possible, but in theory, you could have 2-2, 4-4 etc.
So that has to be #(0), (2 to: limit) allPairsDo: right? Since 2 is the lowest score, 3 the next, 4 = 2 + 2, 5 = 3 + 2, right?
2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
Since the increments include 1 this is equivalent to (0 to: max) allPairsDo: ... i.e. it is possible for a team to continue to score a single point, therefore the possible pairs of scores are all the pairs from 0 to N.
But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com
wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
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On Tue, 5 Jan 2010, John Toohey wrote:
Yes, I think that would do it. What class is #allPairsDo: defined?
It's not defined. Add it to Collection as an extension of your package. Here's Eliot's version: allPairsDo: aBinaryBlock    self do: [:first| self do: [:second| aBinaryBlock value: first value: second]] Levente
2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
Yep, the four scores would be 1 point conversion, 2 point conversion or a safety, 3 point field goal, and a 6 point touchdown. Although the 1 point can only come after a 6 point touchdown, so any score with just a 1 point would not be possible, but in theory, you could have 2-2, 4-4 etc.
So that has to be #(0), (2 to: limit) allPairsDo: right? Since 2 is the lowest score, 3 the next, 4 = 2 + 2, 5 = 3 + 2, right?
2010/1/5 Eliot Miranda <eliot.miranda@gmail.com>
2010/1/5 John Toohey <jt@parspro.com>
:-)
I don't suppose you have an equally elegant solution to the scores for a NFL game, where the units can be 1,2,3,6, assuming that each team could score a total of say, 35 points.
Since the increments include 1 this is equivalent to (0 to: max) allPairsDo: ... i.e. it is possible for a team to continue to score a single point, therefore the possible pairs of scores are all the pairs from 0 to N.
But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
On Tue, Jan 5, 2010 at 21:26, Randal L. Schwartz <merlyn@stonehenge.com
wrote:
"John" == John Toohey <jt@parspro.com> writes:
John> Thank you, duly chastened. I did know the formulae for P and C, but didn't John> know how to add the repetitions. My original code was :- John> |c| John> c := SortedCollection new. John> c add: '0, 0'; add:'1, 1'; add: '2, 2'; add:'3, 3'; add: '4, 4'. John> (0 to: 4) combinations: 2 atATimeDo:[:each | c add: each asCommaString. c John> add:( each reverse) asCommaString].
"Every time I cut with this wide saw, it removes 1/2 inch from the wood! I'll just glue it back after the cuts!"
"why don't you just use the laser cutter? no losses!"
:-)
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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"John" == John Toohey <jt@parspro.com> writes:
John> Yep, the four scores would be 1 point conversion, 2 point conversion or a John> safety, 3 point field goal, and a 6 point touchdown. Although the 1 point John> can only come after a 6 point touchdown, so any score with just a 1 point John> would not be possible, but in theory, you could have 2-2, 4-4 etc. So it isn't really 1, 2, 3, 6. It's 2, 3, 6, 7 maybe? Dunno football - just trying to decipher what you said. -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
On Tue, Jan 05, 2010 at 06:50:51PM -0800, Eliot Miranda wrote:
But isn't American Football more complex? an't you only score 1 after scoring a touchdown? What are the scoring rules? In any case your numbers are so small that you can use brute force and enumerate all possible combinations, filtering totals that exceed your limit.
Yes, brute force is acceptable in American football.
"David" == David T Lewis <lewis@mail.msen.com> writes:
David> Yes, brute force is acceptable in American football. And mandatory in Ozzie Rules. :) -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
2010/1/5 John Toohey <jt@parspro.com>
What I needed to do was from a sequence of say, 0 to: 4, produce #(0 0)#(1 1)#(2 2)#(3 3)#(4 4)#(1 0)#(2 1)#(3 2)#(4 3)#(0 4)#(2 0)#(3 1)#(4 2)#(0 3)#(1 4)#(3 0)#(4 1)#(0 2)#(1 3)#(2 4)#(4 0)#(0 1)#(1 2)#(2 3)#(3 4). Basically, I wanted to generate all possible scores for a soccer match, hence the 1-1, 0-0, etc.
allPairsDo: aBinaryBlock self do: [:first| self do: [:second| aBinaryBlock value: first value: second]] right?
On Tue, Jan 5, 2010 at 19:58, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"Levente" == Levente Uzonyi <leves@elte.hu> writes:
Levente> On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
Levente> I guess you are looking for this: Levente> allPairsFromCollectionDo := [ :collection :block | Levente> | o | Levente> o := OrderedCollection newFrom: collection. Levente> o size timesRepeat: [ Levente> o with: collection do: block. Levente> o add: o removeFirst ] ].
Or more simply:
aCollection do: [:x | aCollection do: [:y | "use x and y"]].
Unless I'm misunderstanding the problem.
Which is neither combinations nor permutations, but so far is the only thing that fits all the bizarre conditions.
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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<blush>oops, just noticed Randal already provided this.</blush> On Tue, Jan 5, 2010 at 5:47 PM, Eliot Miranda <eliot.miranda@gmail.com>wrote:
2010/1/5 John Toohey <jt@parspro.com>
What I needed to do was from a sequence of say, 0 to: 4, produce #(0 0)#(1
1)#(2 2)#(3 3)#(4 4)#(1 0)#(2 1)#(3 2)#(4 3)#(0 4)#(2 0)#(3 1)#(4 2)#(0 3)#(1 4)#(3 0)#(4 1)#(0 2)#(1 3)#(2 4)#(4 0)#(0 1)#(1 2)#(2 3)#(3 4). Basically, I wanted to generate all possible scores for a soccer match, hence the 1-1, 0-0, etc.
allPairsDo: aBinaryBlock self do: [:first| self do: [:second| aBinaryBlock value: first value: second]]
right?
On Tue, Jan 5, 2010 at 19:58, Randal L. Schwartz <merlyn@stonehenge.com>wrote:
"Levente" == Levente Uzonyi <leves@elte.hu> writes:
Levente> On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
Levente> I guess you are looking for this: Levente> allPairsFromCollectionDo := [ :collection :block | Levente> | o | Levente> o := OrderedCollection newFrom: collection. Levente> o size timesRepeat: [ Levente> o with: collection do: block. Levente> o add: o removeFirst ] ].
Or more simply:
aCollection do: [:x | aCollection do: [:y | "use x and y"]].
Unless I'm misunderstanding the problem.
Which is neither combinations nor permutations, but so far is the only thing that fits all the bizarre conditions.
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
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"Eliot" == Eliot Miranda <eliot.miranda@gmail.com> writes:
Eliot> <blush>oops, just noticed Randal already provided this.</blush> "Like ships, passing in the night..." :-) -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
On Tue, 5 Jan 2010, Randal L. Schwartz wrote:
"Levente" == Levente Uzonyi <leves@elte.hu> writes:
Levente> On Tue, 5 Jan 2010, John Toohey wrote:
But this doesn't get 1-1, 2-2 or 3-3. I had tried something like that use #reverse on each combination, but #combinations does not generate -duplicates- from the number sequences.
Levente> I guess you are looking for this: Levente> allPairsFromCollectionDo := [ :collection :block | Levente> | o | Levente> o := OrderedCollection newFrom: collection. Levente> o size timesRepeat: [ Levente> o with: collection do: block. Levente> o add: o removeFirst ] ].
Or more simply:
aCollection do: [:x | aCollection do: [:y | "use x and y"]].
Nice, it's funny that I didn't find this simple solution. And it's O(n^2) instead of O(n^3) like mine (because OrderedCollection is implemented such a dumb way). Levente
Unless I'm misunderstanding the problem.
Which is neither combinations nor permutations, but so far is the only thing that fits all the bizarre conditions.
-- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
participants (7)
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Eliot Miranda -
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