Re: Map function with 2 variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg114951] Re: Map function with 2 variables*From*: Roland Franzius <roland.franzius at uos.de>*Date*: Fri, 24 Dec 2010 04:10:37 -0500 (EST)*References*: <iev2ua$4v6$1@smc.vnet.net>

Am 23.12.2010 09:57, schrieb Jagra: > I have a problem that comes up in a couple of situations and I've > never found the right solution. I hoped I could get an idea of how to > generally address these kinds of things. > > Say I have a function with two variables, something like a > SpearmanRankCorrelation[] from the MultiVariate Statistics package: > > I also have matrix "m" with dimensions {3, 100} > > m = RandomReal[{0, 1}, {3, 100}]; > > Now, say I want to create a correlation matrix using the > SpearmanRankCorrelation function. > > I can get the rank correlations between a single vector of the matrix > and all the other vectors like this: > > SpearmanRankCorrelation[m[[1]], #]& /@ m > > This would give me a single row in a correlation matrix. Pretty > straightforward, but now I want all 3 rows like I would get with this: > > {SpearmanRankCorrelation[m[[1]], #]& /@ m, > SpearmanRankCorrelation[m[[2]], #]& /@ m, > SpearmanRankCorrelation[m[[3]], #]& /@ m} > > There must be a way I can do this more directly. > I must be missing something simple. Two possibilities to generate product arrays from a given one: Array[SpearmanRankCorrelation[m[[#1]], m[[#2]]] &, Length[m] {1, 1}] Outer[SpearmanRankCorrelation, m, m, 1] -- Roland Franzius