# Re: String patterns

• To: mathgroup@smc.vnet.net
• Subject: [mg10930] Re: String patterns
• From: Paul Abbott <paul@physics.uwa.edu.au>
• Date: Thu, 12 Feb 1998 20:16:13 -0500
• Organization: University of Western Australia
• References: <6brf6t\$e78@smc.vnet.net>

```MJE wrote:

> How good is Mathematica at this kind of string manipultion and
> searching?

Here is a basic implementation:

In[1]:= string="I love Mathematica"; In[2]:= chars=Characters[string]
In[3]:= ToUpperCase[chars]

Select all upper case letters (and " ",".","-",":"):

In[4]:= Select[%,UpperCaseQ[#]||
MemberQ[ToCharacterCode/@{" ",".","-",":"},ToCharacterCode[#]]&]

Form the trigraphs explicitly

In[5]:= trigraphs=Apply[StringJoin,Partition[%,3,1],{1}]

and compute the frequencies:

In[6]:=<<Statistics`DataManipulation` In[6]:=
Reverse/@(Frequencies[trigraphs]//Sort//Reverse)//TableForm

Out[6]//TableForm=
MAT   2
VE    1
TIC   1
THE   1
OVE   1
MA   1
...

There is probably a neat pattern-matching way of computing the
frequencies without constructing the trigraphs explicitly.

Cheers,
Paul

____________________________________________________________________
Paul Abbott                                   Phone: +61-8-9380-2734
Department of Physics                           Fax: +61-8-9380-1014
The University of Western Australia            Nedlands WA  6907
mailto:paul@physics.uwa.edu.au  AUSTRALIA
http://www.pd.uwa.edu.au/~paul

God IS a weakly left-handed dice player
____________________________________________________________________

```

• Prev by Date: Re: NDSolve vs. DSolve
• Next by Date: Re: Active Plots
• Prev by thread: String patterns
• Next by thread: Re: String patterns