Re: Position
- To: mathgroup at smc.vnet.net
- Subject: [mg131131] Re: Position
- From: "Alexander Elkins" <alexander_elkins at hotmail.com>
- Date: Fri, 14 Jun 2013 04:56:15 -0400 (EDT)
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- Delivered-to: l-mathgroup@wolfram.com
- Delivered-to: mathgroup-outx@smc.vnet.net
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- References: <kpbp24$95n$1@smc.vnet.net>
Use Condition(/;) on a Pattern named x matching any Real to test x for
Greater than 2.0 like so:
In[1]:=
Position[{1.4,3.5,2.1,-1.2},x_Real/;x>2.]
Out[1]=
{{2},{3}}
In[2]:=
FullForm[x_Real /; x > 2.]
Out[2]=
Condition[Pattern[x, Blank[Real]], Greater[x, 2.`]]
Or use PatternTest on an unnamed pattern matching any Real to test it for
Greater than 2.0 like so:
In[3]:=
Position[{1.4,3.5,2.1,-1.2},_Real?(#>2.&)]
Out[3]=
{{2},{3}}
In[4]:=
FullForm[_Real?(#>2.&)]
Out[4]//FullForm=
PatternTest[Blank[Real],Function[Greater[Slot[1],2.`]]]
"Costa Bravo" <q13a27tt at aol.com> wrote in message
news:kpbp24$95n$1 at smc.vnet.net...
> How can I find the indices of all elements greaters than e.g. 2 of a
vector.
>
> t=RandomReal[{0,5},100]
> Position[t,??]
>
> --
> Costa
>