Re: Mapping A Condition Across Two Different Lists

*To*: mathgroup at smc.vnet.net*Subject*: [mg91754] Re: Mapping A Condition Across Two Different Lists*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Sun, 7 Sep 2008 05:36:28 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <g9t6k5$j6g$1@smc.vnet.net>

Gregory Lypny wrote: > Not sure how to do this using Map, or even if it's possible. > > I can compare a target value to each value in a list like this. > > targetX = 5; listX = {4, 9, 2, 11, 4}; > targetX > # & /@ listX > > {True, False, True, False, True} > > I can do the same for another target and another list. > > targetY = 3; listY = {4, 0, 1, 8, 6}; > targetY > # & /@ listY > > {False, True, True, False, False} > > But can I do it in a similar way for the AND or OR condition without > having to resort to the Table command? > > Table[targetX > listX[[i]] && targetY > listY[[i]], {i, Length@listX}] > > {False, False, True, False, False} > > Table[targetX > listX[[i]] || targetY > listY[[i]], {i, Length@listX}] > > {True, True, True, False, True} Among other ways, you could map over the transpose of list of the two lists, e.g. In[1]:= targetX = 5; listX = {4, 9, 2, 11, 4}; targetY = 3; listY = {4, 0, 1, 8, 6}; targetX > #[[1]] && targetY > #[[2]] & /@ Transpose[{listX, listY}] targetX > #[[1]] || targetY > #[[2]] & /@ Transpose[{listX, listY}] Out[3]= {False, False, True, False, False} Out[4]= {True, True, True, False, True} Best regards, -- Jean-Marc