Re: Test of a pure function
- To: mathgroup at smc.vnet.net
- Subject: [mg34041] Re: [mg34010] Test of a pure function
- From: BobHanlon at aol.com
- Date: Sat, 27 Apr 2002 00:57:14 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 4/26/02 5:11:41 AM, soconnor at ccs.nrl.navy.mil writes:
>I hope someone can help me with this I know the solution should be easy
>but I am still learning how pure functions work.
>
>I am trying to pick out a position in a list were a number falls i.e.
>
>Position[xBins, _?(#1<=x <= #2 &)]. I keep getting errors Like these
>
>
>Function::slotn: Slot number 2 in #1 x #2& cannot be filled
>from \
>(#1 x #2&)[List].
>
>Function::slotn: Slot number 2 in
>#1 x #2& cannot be filled from \
>(#1 x #2&)[-1].
>
>From
>In[83]:=
>Function::slotn: Slot number 2 in #1 x #2& cannot be filled from
>\
>(#1 x #2&)[-0.995].
>
>General::stop: Further output of
>Function::slotn will be suppressed during \
>this calculation.
>
>
>Can I make a comparison with the nth and nth+1 element in a pure function.
>
Rather than trying to compare x to two adjacent values, restructure the
question to count the number of values less than or equal to x.
myPosition[xBins_?VectorQ, x_?NumericQ] :=
Count[xBins, _?(#<=x&)]+1;
data = Sort[Table[Random[], {10}]]
{0.08812644925276472,
0.10010226701182356,
0.4254438313086471,
0.4540738901849056,
0.5471335846922069,
0.6297724295620055,
0.725499086248874,
0.8527355066955329,
0.8919613144350851,
0.9392439737457312}
myPosition[data, .5]
5
Bob Hanlon
Chantilly, VA USA