Re: Mapping A Condition Across Two Different Lists

*To*: mathgroup at smc.vnet.net*Subject*: [mg91738] Re: [mg91705] Mapping A Condition Across Two Different Lists*From*: Gregory Lypny <gregory.lypny at videotron.ca>*Date*: Sun, 7 Sep 2008 05:33:26 -0400 (EDT)*References*: <20080906091553.7CU18.147801.imail@eastrmwml41>

Thank you, Jean-Marc and Bob, Elegant solutions. I find the one with Transpose to be more intuitive because it's not obvious that Thread is threading the joint comparison, which it is, and which I guess is another example of Mathematica's scope. Regards and thanks again, Gregory On Sat, Sep 6, 2008, at 11:56 AM, Jean-Marc Gulliet wrote: > > 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 > On Sat, Sep 6, 2008, at 9:15 AM, Bob Hanlon wrote: > targetX = 5; listX = {4, 9, 2, 11, 4}; > > targetY = 3; listY = {4, 0, 1, 8, 6}; > > Thread[(targetX > # & /@ listX) && > (targetY > # & /@ listY)] > > {False,False,True,False,False} > > targetX > #[[1]] && targetY > #[[2]] & /@ > Transpose[{listX, listY}] > > {False,False,True,False,False} > > % == %% > > True > > Thread[(targetX > # & /@ listX) || > (targetY > # & /@ listY)] > > {True,True,True,False,True} > > targetX > #[[1]] || targetY > #[[2]] & /@ > Transpose[{listX, listY}] > > {True,True,True,False,True} > > % == %% > > True > > > Bob Hanlon > > ---- Gregory Lypny <gregory.lypny at videotron.ca> wrote: > > ============= > Hello everyone, > > 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} > > Much obliged, > > Gregory > > > -- > > Bob Hanlon >