Re: Nested list - adding to each entry

• To: mathgroup at smc.vnet.net
• Subject: [mg113036] Re: Nested list - adding to each entry
• From: Thomas Dowling <thomasgdowling at gmail.com>
• Date: Tue, 12 Oct 2010 04:23:16 -0400 (EDT)

```Hello,

Transpose@({1, 2} + Transpose@{{a, b}, {c, d}})

is one way.

Tom Dowling

On Mon, Oct 11, 2010 at 10:16 AM, Sebastian Schmitt <
sschmitt at physi.uni-heidelberg.de> wrote:

> Dear all!
>
> (I recycle my disclaimer.)
>
> I'm new to Mathematica with a background mostly in C++. Many times I
> have the impression that my style is not natural-Mathematica
> (Mathematicaesque so to say).
>
> I want to add something (an absolute position) to each entry (a relative
> position) of a list. This works as expected in the 1D case:
>
> In[43]:= 1 + {2, 3, 4}
>
> Out[43]= {3, 4, 5}
>
> But the 2D case is different because my list of relative positions is
> interpreted as a matrix:
>
> In[57]:= {1, 2} + {{a, b}, {c, d}}
>
> Out[57]= {{1 + a, 1 + b}, {2 + c, 2 + d}}
>
> I would like to get
>
> {{1 + a, 2 + b}, {1 + c, 2 + d}}
>
>
> I know I can achieve it with the help of a pure function:
>
> In[58]:= Map[# + {1, 2} &, {{a, b}, {c, d}}]
>
> Out[58]= {{1 + a, 2 + b}, {1 + c, 2 + d}}
>
> Is there a builtin function that does the same? I'm somehow reluctant to
> use pure functions too much. Is my concern unfounded?
>