Re: Pattern: x_List with conditions on elements
- To: mathgroup at smc.vnet.net
- Subject: [mg110845] Re: Pattern: x_List with conditions on elements
- From: "Sir Bob Knight" <sir.bob.knight at gmail.com>
- Date: Thu, 8 Jul 2010 06:50:21 -0400 (EDT)
What about the followings?
In[2]:== MatchQ[{1, 2, 2.2, 5, 6, 4, 3, 3.}, {(_Real | _Integer) ..}]
Out[2]== True
In[3]:== MatchQ[{1 + I, 2, 2.2, 5, 6, 4, 3, 3.}, {(_Real | _Integer) ..}]
Out[3]== False
In[4]:== MatchQ[N[{1, 2, 2.2, 5, 6, 4, 3, 3.}], {_Real ..}]
Out[4]== True
In[5]:== MatchQ[N[{1 + I, 2, 2.2, 5, 6, 4, 3, 3.}], {_Real ..}]
Out[5]== False
In[6]:== MatchQ[{1, 2, 2.2, 5, 6, 4, 3.}, {_?(# \[Element] Reals &) ..}]
Out[6]== True
In[7]:== MatchQ[{1 + I, 2, 2.2, 5, 6, 4, 3.}, {_?(# \[Element] Reals &) ..}=
]
Out[7]== False
In[8]:== MatchQ[{a, b, c, d, e, f}, {_Symbol ..}]
Out[8]== True
In[9]:== MatchQ[{1, a, b, c, d, e, f}, {_Symbol ..}]
Out[9]== False
-Bob-
> -----Messaggio originale-----
> Da: telefunkenvf14 [mailto:rgorka at gmail.com]
> Inviato: gioved=EC 8 luglio 2010 9.14
> A: mathgroup at smc.vnet.net
> Oggetto: [mg110829] Pattern: x_List with conditions on elements
>
> Group:
>
> 1. Can someone provide a clearer way of implementing the following
> example? (Goal: I want a pattern that accepts only a list of real
> numbers and what I have seems hacky.)
>
> MatchQ[{1, 2, 2.2},x_?(VectorQ[#,(NumericQ[#]&&Im[#]====0)&]&)]
>
> 2. Could someone show me how to create a second pattern which accepts
> only a list (vector) of symbols? I feel like I'm spinning my wheels a
> bit on this one...
>
> 3. Does anyone else think it would be nice to compile a list of
> favorite/useful patterns, along with a very brief explanation of the
> intent? (And yes, I know there are a bunch of examples in the
> documentation(!), but I'm thinking more in terms of assembling a list
> of recipes.) I guess I'm just craving more guided examples.
>
> -RG