Re: Converting 2D Lists to 3D lists

• To: mathgroup at smc.vnet.net
• Subject: [mg94963] Re: [mg94941] Converting 2D Lists to 3D lists
• From: "Scot T. Martin" <smartin at deas.harvard.edu>
• Date: Thu, 1 Jan 2009 07:26:20 -0500 (EST)
• References: <200812311108.GAA13561@smc.vnet.net>

```Karthik,

I think these show you how to do it:

In[12]:=
SampleList3D={{{-1,2},{0,1},{3,4}},{{-3,-2},{-1.5,2.5},{0.5,-.75}}}

Out[12]= {{{-1,2},{0,1},{3,4}},{{-3,-2},{-1.5,2.5},{0.5,-0.75}}}

In[18]:= Map[Append[#,5]&,SampleList3D,{2}]

Out[18]=
{{{-1,2,5},{0,1,5},{3,4,5}},{{-3,-2,5},{-1.5,2.5,5},{0.5,-0.75,5}}}

In[19]:= ReplacePart[%,{2,2,3}->3]

Out[19]=
{{{-1,2,5},{0,1,5},{3,4,5}},{{-3,-2,5},{-1.5,2.5,3},{0.5,-0.75,5}}}

On Wed, 31 Dec 2008, Karthik Sridhara wrote:

> Hello Everyone,
>
> I want to know if there is a way to convert a 2D lists to 3D Lists.
> Below is the example list in list form:
>
> SampleList3D = {{{-1, 2}, {0, 1}, {3, 4}}, {{-3, -2}, {-1.5, 2.5},
> {0.5, -.75}}}
>
> I want the list to be intact but add 5 at the end of each sublist;
> This is how I want it to look:
>
> {{{-1, 2, 5}, {0, 1, 5}, {3, 4, 5}}, {{-3, -2, 5}, {-1.5, 2.5, 5},
> {0.5, -.75, 5}}}
>
> I also want to be able do the same as above but add 3 this time to the
> second column. This is how it should look.
> {{{-1, 2, 5}, {0, 1, 5}, {3, 4, 5}}, {{-3, -2, 3}, {-1.5, 2.5, 3},
> {0.5, -.75, 3}}}
>
> Is there any way I can do this? I have been trying to use Map and
> Insert but I am getting the wrong result.
>
> Insert[SampleList3d, x, {#, -1}] & /@ {1, 2} ;
>
> I get this result and this is not what I want:
> {{{{-1, 2}, {0, 1}, {3, 4},
>   x}, {{-3, -2}, {-1.5, 2.5}, {0.5, -0.75}}}, {{{-1, 2}, {0, 1}, {3,
>    4}}, {{-3, -2}, {-1.5, 2.5}, {0.5, -0.75}, x}}}
>
>