Re: Simplest way to get 2 digits from an integer...
- To: mathgroup at smc.vnet.net
- Subject: [mg110937] Re: Simplest way to get 2 digits from an integer...
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Mon, 12 Jul 2010 07:22:01 -0400 (EDT)
On 7/12/10 at 1:04 AM, rodrigomurtax at gmail.com (Murta) wrote:
>Hello All
>
>I would like to find a simplest code to take the first n digits os a
>integer. Here are two examples (not simple) to take the first 2
>digits os the number a:
>1) a = 1234; ToExpression@StringTake[ToString[a], 2]
>12
>2) a = 1234;
>FromDigits@Take[IntegerDigits[a],2]
>12
Simplest is somewhat subjective. Here are two other ways:
In[2]:= Floor[10^(1 + FractionalPart[Log[10, a]])]
Out[2]= 12
In[3]:= FromDigits[RealDigits[a] /. {a_, _} :> {a[[;; 2]], 2}]
Out[3]= 12
This last will return the first two significant digits of any
real number regardless of where the decimal point is.