Rank: 2136 based on 24 downloads (last 30 days) and 9 files submitted

Peter Cotton

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Company/University: Benchmark Solutions

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Files Posted by Peter					View all 1 - 5 of 9
Updated		File	Tags	Downloads (last 30 days)	Comments	Rating
16 Aug 2010		intent.m Graphically display mfiles, and naive intent Author: Peter Cotton	bioplot, files, functional, dir	2	0
16 Aug 2010		signature Parse function argument names from an mfile or anonymous function handle Author: Peter Cotton	mfile, arguments, nargin, nargout, varargout, varargin	3	0
16 Aug 2010		bernpdf Distribution of the sum of independent non-identical Bernoulli random variables using convolution Author: Peter Cotton	statistics, probability, simulation, bernoulli, convolution, conv	2	0
15 Aug 2010		harville The Harville method for exacta, quinella and trifecta probabilities Author: Peter Cotton	harville, statistics, probability, trifecta, exacta, quinella	0	0
15 Aug 2010		ability ABILITY - Infer ability from probability of winning a competition Author: Peter Cotton	gev, statistics, generalized, extreme value, probability, order statistics	1	0

Comments and Ratings by Peter		View all 1 - 5 of 16
Updated	File	Comments	Rating
29 Sep 2011	vecgcd Computes the GCD of the elements of the integer vector V. Author: Steven Gregory	typo on line 47?
28 Oct 2010	Automated composition of function handles Automatically compose function handles Author: Peter Cotton	I prefer and maintain functor.m (also on Matlab Central) rather than this code.
07 Sep 2010	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML Author: Jaroslaw Tuszynski	Can I suggest a small modification to xml_read so that sparse matrices are returned as sparse matrices rather than a string describing their construction (to be passed to eval)?
16 Aug 2010	Non-Uniform Bernoulli Trials Exceedance Probability Calculates the probability of exceeding a given number of hits for a collection of Bernoulli trials Author: William	William, I was looking for the same thing and ended up re-writing it myself (bernpdf.m). Let me know if you come across other analytic implementations (e.g. by Fourier transform). I think you mean 'non-uniform p', for otherwise you can use binopdf.m in the stats toolbox. Peter ps: Sorry you find analytical statistics tiresome
04 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Hi Andy, Apologies for my tardiness in replying and your suggestions are well intentioned. Small quibbles over timing are mere definitional (I need the right order - thus included sortrows) but potentially larger philosophical differences relate to the stability and maintainability of code (of which nsumk.m is a very tiny piece). I generally refrain from giving others style or programming advice but using a great honking general function might not always be the best decision when it can be accomplished either by three lines of code, or a teeny weeny function such as nsumk.m ... not that I knowingly made a conscious decision given my ignorance. No justification is required for reducing code complexity but I leave the rants to others. I suggest googling "premature generalization", for example. Regards, Peter

Comments and Ratings on Peter's Files			View all 1 - 5 of 29
Updated	File	Comment by	Comments	Rating
18 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Campbell, Rob	I have no use for this function but the above discussion is wonderful.
15 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Cotton, Peter	Thanks Jan, I'll update the description Peter
12 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Sean	Ha ha ha! I thoroughly enjoyed this very entertaining discussion!
06 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Simon, Jan	VCHOOSEK is a Mex, which is > factor 100 faster than NCHOOSEK: http://www.mathworks.com/matlabcentral/fileexchange/26190 You do not have to check twice, if n and k are scalars: if ~isscalar(n) \|\| ~isscalar(k); error(...); end m = nchoosek(k+n-1,n-1); if nargout == 2 dividers = [zeros(m,1), vchoosek((1:(k+n-1))',n-1),ones(m,1)*(k+n)]; x = diff(dividers,1,2)-1; end Congratulation for the great discussion! Jan
04 Aug 2010	nsumk Returns the number and listing of n-tuples of non-negative integers adding up to k. Author: Peter Cotton	Cotton, Peter	Hi Andy, Apologies for my tardiness in replying and your suggestions are well intentioned. Small quibbles over timing are mere definitional (I need the right order - thus included sortrows) but potentially larger philosophical differences relate to the stability and maintainability of code (of which nsumk.m is a very tiny piece). I generally refrain from giving others style or programming advice but using a great honking general function might not always be the best decision when it can be accomplished either by three lines of code, or a teeny weeny function such as nsumk.m ... not that I knowingly made a conscious decision given my ignorance. No justification is required for reducing code complexity but I leave the rants to others. I suggest googling "premature generalization", for example. Regards, Peter

Top Tags Applied by Peter	1 - 5 of 59
statistics, probability, data export, exacta, quinella

Files Tagged by Peter					View all 1 - 5 of 14
Updated		File	Tags	Downloads (last 30 days)	Comments	Rating
16 Aug 2010		intent.m Graphically display mfiles, and naive intent Author: Peter Cotton	bioplot, files, functional, dir	2	0
16 Aug 2010		signature Parse function argument names from an mfile or anonymous function handle Author: Peter Cotton	mfile, arguments, nargin, nargout, varargout, varargin	3	0
16 Aug 2010		bernpdf Distribution of the sum of independent non-identical Bernoulli random variables using convolution Author: Peter Cotton	statistics, probability, simulation, bernoulli, convolution, conv	2	0
15 Aug 2010		harville The Harville method for exacta, quinella and trifecta probabilities Author: Peter Cotton	harville, statistics, probability, trifecta, exacta, quinella	0	0
15 Aug 2010		ability ABILITY - Infer ability from probability of winning a competition Author: Peter Cotton	gev, statistics, generalized, extreme value, probability, order statistics	1	0

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Files Matching Peter's Watch List					View all 1 - 5 of 8
Updated		File	Tags	Downloads (last 30 days)	Comments	Rating
05 Nov 2010		xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML Author: Jaroslaw Tuszynski	xmlwrite, data import, xml, tools, data export, xmlread	132	64	4.83784 4.8 \| 38 ratings
16 Aug 2010		intent.m Graphically display mfiles, and naive intent Author: Peter Cotton	bioplot, files, functional, dir	2	0
16 Aug 2010		signature Parse function argument names from an mfile or anonymous function handle Author: Peter Cotton	mfile, arguments, nargin, nargout, varargout, varargin	3	0
16 Aug 2010		bernpdf Distribution of the sum of independent non-identical Bernoulli random variables using convolution Author: Peter Cotton	statistics, probability, simulation, bernoulli, convolution, conv	2	0
15 Aug 2010		harville The Harville method for exacta, quinella and trifecta probabilities Author: Peter Cotton	harville, statistics, probability, trifecta, exacta, quinella	0	0

Comments and Ratings Matching Peter's Watch List			1-5 of 69
Date	File	Comment by	Comments	Rating
02 Jan 2012	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML	Daniel	Hej, I just noticed, that the xml_read function does not detect arrays correctly from attributes of xml-nodes. I use the str2num=smart default option. I found, that there is an error in the str2var function on line 452 where I just removed the square brackets from the digit array: digits = '(Inf)\|(NaN)\|(pi)\|[\t\n\d\+\-\*\.ei EI\;\,]'; Now it works again like a charm. Great work by the way. Hope you can add the bugfix to a future release. Daniel	Comment only
22 Dec 2011	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML	John Clayton	Jaroslaw, Thanks for this excellent work. I enjoy using it, so I wanted to share what I did to possibly improve "xml_read". Reading in the following .xml file: <?xml version="1.0" encoding="utf-8"?> <ROOT> <xtr_base> <item>0x30010</item> </xtr_base> <reg_base>0x30000</reg_base> <pcm_base> <item>0x30040</item> <item>0x30050</item> </pcm_base> </ROOT> I performed the following commands: >> D3=xml_read('testrdsmall_jec.xml'); >> D3 D3 = xtr_base: '0x30010' reg_base: '0x30000' pcm_base: {'0x30040' '0x30050'} It bothered me that the resulting data structure in Matlab has both xtr_base and reg_base the same. I tried using Pref.CellItem=true, as in the following commands: >> Pref.CellItem=true; >> D2=xml_read('testrdsmall_jec.xml',Pref); >> D2 D2 = xtr_base: {'0x30010'} reg_base: '0x30000' pcm_base: {{1x2 cell}} This did produce a difference between xtr_base and reg_base, but the pcm_base was now a cell-array within a cell-array! So, I decided to make a modification to your code... So now, with my small modification, I do the following commands: >> D5=xml_read_jec('testrdsmall_jec.xml'); >> D5 D5 = xtr_base: {'0x30010'} reg_base: '0x30000' pcm_base: {'0x30040' '0x30050'} It produces the result I expect. However, when I use Pref.CellItem=true, I get: >> D=xml_read_jec('testrdsmall_jec.xml',Pref); >> D D = xtr_base: {'0x30010'} reg_base: '0x30000' pcm_base: {{1x2 cell}} ... which is probably not exactly as it should be. So, maybe my modification is not entirely correct. What I did was to change lines 383-387 from this: if (isfield(s,Pref.ItemName)) s.CONTENT = s.(Pref.ItemName); s = rmfield(s,Pref.ItemName); ItemContent = Pref.CellItem; % if CellItem than keep s.CONTENT as cells end to be this instead: if (isfield(s,Pref.ItemName)) % Check for singleton nodes that have the special keyword to mark arrays, % and keep them as cell arrays, even though the resulting cell array % only has one member. -- Modification by John Clayton, 12/22/11. if ~iscell(s.(Pref.ItemName)) s.CONTENT = s.(Pref.ItemName); s = rmfield(s,Pref.ItemName); ItemContent = true; else s.CONTENT = s.(Pref.ItemName); s = rmfield(s,Pref.ItemName); ItemContent = Pref.CellItem; % if CellItem then keep s.CONTENT as cells end end What do you think of this change? Perhaps I did it not very well, but I wanted to tell you about it. Thanks again for your excellent work! - John Clayton	5
14 Dec 2011	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML	Edward Carney		5
23 Sep 2011	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML	Antoan Nikolaev		5
10 Aug 2011	xml_io_tools Read XML files into MATLAB struct and writes MATLAB data types to XML	Andrew	Brilliant, just what I was looking for.	5

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