Re: Select x s.t. y>10

*To*: mathgroup at smc.vnet.net*Subject*: [mg14001] Re: Select x s.t. y>10*From*: Leszek Sczaniecki <lsczan at concentric.net>*Date*: Sat, 12 Sep 1998 16:59:23 -0400*Organization*: Concentric Internet Services*References*: <6tbtv8$mq0@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Is there any reson that you can't use directly a build-in function Select as in the following example? In[1]:= lst = Table[{Random[], Random[]}, {10}] Out[1]= {{0.87642,0.859277},{0.990313,0.434662},{0.631448,0.153609},{0.515145, 0.424282},{0.00339491,0.575325},{0.562473,0.690501},{0.817277,0.713543},{ 0.709017,0.351955},{0.937637,0.0728005},{0.553451,0.791334}} In[1]:= Select[lst, #[[2]] < .5 &] Out[1]= {{0.990313,0.434662},{0.631448,0.153609},{0.515145,0.424282},{0.709017, 0.351955},{0.937637,0.0728005}} -- Leszek Jason Gill wrote: > I came across what seems like it should be a simple little function, but > could not come up with a clever way to implement it. Generally, what I > am trying to do is take a list of lists of length 2 ie a list of x,y > coordinates, and Select x values based on some criterion for y. For > example I want to select the first x value for which the corresponding > y is greater than 5. > I can write a function using Position and Take etc. , but there must be > a clever,and more efficient way to do this. Any thoughts... Jason > > -- > Jason Gill > IBM Microelectronics > Essex Junction, VT 05452 > Phone (802)769-3350 > Fax (802)769-1220 > email: jgill at vbimail.champlain.edu > jasongil at us.ibm.com