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Topic: Hold & Evaluate
Replies: 4   Last Post: Feb 25, 2013 2:20 AM

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Tomas Garza Hernandez

Posts: 264
Registered: 4/15/05
Re: Hold & Evaluate
Posted: Feb 25, 2013 2:20 AM
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Sorry, I should have given the complete answer to your question. As I assume you only want to print the sequence in the fraction-like form, do as follows:
In[1]:= b=Rationalize/@Table[n/(n+0.1 (n+1)),{n,1,15}]Out[1]= {5/6,20/23,15/17,8/9,25/28,60/67,35/39,80/89,9/10,100/111,55/61,120/133,65/72,28/31,75/83}
In[2]:= d=Table[j,{j,1,15}]Out[2]= {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}
In[3]:= c=(1./b)d Out[3]= {1.2,2.3,3.4,4.5,5.6,6.7,7.8,8.9,10.,11.1,12.2,13.3,14.4,15.5,16.6}
In[4]:= Table[ToString[d[[j]]]<>"/"<>ToString[c[[j]]],{j,1,15}]Out[4]= {1/1.2,2/2.3,3/3.4,4/4.5,5/5.6,6/6.7,7/7.8,8/8.9,9/10=
.,10/11.1,11/12.2,12/13.3,13/14.4,14/15.5,15/16.6}
-Tomas

> From: Serych@panska.cz
> Subject: Hold & Evaluate
> To: mathgroup@smc.vnet.net
> Date: Sat, 23 Feb 2013 23:31:40 -0500
>
> Dear mathgroup,
> I would like to generate sequence in the form:
>
> 1/1.2, 2/2.3, 3/3.4, 4/4.5, etc.
>
> It is very simple by a Table function:
>
> Table[n/(n + 0.1 (n + 1)), {n, 1, 15}]
>
> but as there are real numbers in denominators, Mathematica evaluates all and generates something like:
>
> {0.833333, 0.869565, 0.882353, 0.888889, 0.892857, 0.895522, etc.}
>
> How to evaluate numerators and denominators separately and print the sequence in that "fraction like" form?
>
> I tested:
>
> #[[1]]/#[[2]] & /@ Table[{n, n + 0.1 (n + 1)}, {n, 1, 15}] and than used Hold[] and Evaluate[]:
>
> Hold[Evaluate[#[[1]]]/Evaluate[#[[2]]]] & /@
> Table[{n, n + 0.1 (n + 1)}, {n, 1, 15}]
>
> But it doesn't work as the Hold has "veto" power over any evaluation.
>
> Thanks in advance for any idea, how to do it
>
> Jakub
>





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