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Re: Through[Divide[f1, f2][x]]
Posted:
May 28, 2013 3:48 AM


On Sun, May 26, 2013 @ 11:23 AM, Andrzej Kozlowski <akozlowski@gmail.com> wrote: > On 26 May 2013, at 11:06, Ray Koopman <koopman@sfu.ca> wrote: > >> Either of these will give you f1[x]/f2[x]: >> >> Divide@@{f1@#,f2@#}&@x >> >> Divide@@(#@x&)/@{f1,f2} >> >> Sometimes it would be nice to have a "reverse map", that >> applied each of a list of functions to a single argument, >> instead of a single function to each of a list of arguments. > > I am not sure I understand what you mean. Why doesn't Through do that? > > Through[{f, g, h}[x]] > > {f[x], g[x], h[x]} > > Andrzej Kozlowski
Through does do that. When I saw Bob's response to the original post I asked myself "How did I miss that?" I thought I had tried it and found that it didn't work. The only explanation I can think of is that I had the "reverse map" metaphor fixed too firmly in my mind, to the point that I used Maplike syntax [{f1,f2},x] instead of [{f1,f2}@x].



