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Topic: Adding value to some elements of a list
Replies: 5   Last Post: Jun 6, 2013 11:14 PM

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 Sseziwa Mukasa Posts: 108 Registered: 8/26/07
Re: Adding value to some elements of a list
Posted: Jun 6, 2013 7:24 AM

On option:

(Debug) In[1]:= a = {10, 20, 30, 40, 50, 60};

b = {2, 4, 6};

c = 17;
(Debug) In[4]:= a[[#]] += c & /@ b
(Debug) Out[4]= {37, 57, 77}
(Debug) In[5]:= a
(Debug) Out[5]= {10, 37, 30, 57, 50, 77}

On Jun 5, 2013, at 3:27 AM, Joerg Lenhardt <joerg.lenhardt@FernUni-Hagen.de> wrote:

> Hello,
>
> I have two lists. One containing values, another containing indexes to
> the first list. I want to add a value to all elements of the first list
> when its index is in the second list:
>
> a={10,20,30,40,50,60}
>
> b={2,4,6}
>
> c=17
>
> ==>
>
> {10,20+17,30,40+17,50,60+17}
>
> I would be glad if anyone have a simple solution for that problem - I am
> convinced there is one ...
>
> Best regards
> J. Lenhardt
>

Date Subject Author
6/5/13 Ulrich Arndt