Apply a function to parts of a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg110299] Apply a function to parts of a list*From*: Rui <rui.rojo at gmail.com>*Date*: Sat, 12 Jun 2010 05:32:38 -0400 (EDT)

I have always done very ugly code when trying to do something seemingly simple and basic such as applying a function to subparts of a list. Simple example, I want to divide by 2 all the second elements of a list {{a, 5}, {b, 6}, ...} --> {{a, 5/2}, ...} My ideas: Transpose -> MapAt/Map -> Transpose Build the sublist with Part and then rebuild it Use Map and a function like #[[All, 2]] and then rebuild it. I don't like any solution. I wanted to know if there's anything simple that I'm overseing Thanks guys