Re: Adding value to some elements of a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg131049] Re: Adding value to some elements of a list*From*: Sseziwa Mukasa <mukasa at gmail.com>*Date*: Thu, 6 Jun 2013 07:29:28 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130605072741.946F96A19@smc.vnet.net>

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 at 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 >

**References**:**Adding value to some elements of a list***From:*Joerg Lenhardt <joerg.lenhardt@FernUni-Hagen.de>