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Re:Select xs.t.y>10

• To: mathgroup at smc.vnet.net
• Subject: [mg13992] Re:Select xs.t.y>10
• From: Allan Hayes <hay at haystack.demon.co.uk>
• Date: Sat, 12 Sep 1998 16:59:16 -0400
• Sender: owner-wri-mathgroup at wolfram.com

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:

data= {{1,2},{2,6},{3,6}};

Cases[data,{x_,y_}/;y>5->x, {1},1]

{2}

Allan
-- 
Allan Hayes
Training and Consulting
Leicester, UK
hay at haystack.demon.co.uk
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