Re: Picking Off Lists That Have No Numbers

• To: mathgroup at smc.vnet.net
• Subject: [mg99523] Re: Picking Off Lists That Have No Numbers
• From: Ulvi Yurtsever <a at b.c>
• Date: Thu, 7 May 2009 06:35:07 -0400 (EDT)
• References: <gtrl29\$1o5\$1@smc.vnet.net>

```Gregory Lypny <gregory.lypny at videotron.ca> wrote in news:gtrl29\$1o5\$1
@smc.vnet.net:

> Hi everyone,
>
> In a previous thread, "Select and Cases Give Different Answers," I
> discussed a bug, confirmed by others on the list and which Daniel
> Lichtblau of Wolfram said has been fixed in the development kernel,
> and I wonder whether we have the same problem here.
>
> I want to know if a list has no numbers in it.  Here I get the wrong
> answer for the first list.
>
> FreeQ[#, _Number] & /@ {{"NA", 2.3, 3/8}, {"NA", "NA", "NA"}}
>
> yields {True, True}
> And same here.
>
> MemberQ[#, _Number] & /@ {{"NA", 2.3, 3/8}, {"NA", "NA", "NA"}}
>
> {False, False}
>
> If I use Real or Rational for the criterion, I get the right answers,
> but that's no good if you have some lists that are mixtures of strings
> and reals and others that are mixtures of strings and rationals.

I don't think _Number is a built-in pattern match,
unlike _Real, _Rational, _String, or _Integer.

In[29]:= FreeQ[#, _?NumberQ] & /@ {{"NA", 2.3, 3/8}, {"NA", "NA", "NA"}}

Out[29]= {False, True}

In[30]:= MemberQ[#, _?NumberQ] & /@ {{"NA", 2.3, 3/8}, {"NA", "NA", "NA"}}

Out[30]= {True, False}

In[32]:=
Count[#, _?NumberQ] == 0 & /@ {{"NA", 2.3, 3/8}, {"NA", "NA", "NA"}}

Out[32]= {False, True}

Ulvi

```

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