Re: complicated list selector
- To: mathgroup at smc.vnet.net
- Subject: [mg98480] Re: complicated list selector
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Fri, 10 Apr 2009 04:58:07 -0400 (EDT)
On 4/9/09 at 5:55 AM, summertan at hotmail.com (summer) wrote:
>I have the following list
>data = { {11, {121, 122}}, {21, {221, 222}}, {31, {321, 322}} };
>From each sublist, I want to extract the first element and the second
>element of the second sub-sub-list that is:
>wanted_result={ {11, 122}, {21, 222}, {31, 322} }
>I tried
>data[[All, {1, {2,1}}]]
>but it gives me error.
>What is the right selector ?
Here are three ways to achieve your desired result
In[3]:= data[[All, 2]]
Out[3]= {{121, 122}, {221, 222}, {321, 322}}
In[4]:= Last /@ data
Out[4]= {{121, 122}, {221, 222}, {321, 322}}
In[5]:= data /. {a_, b_} -> b
Out[5]= {{121, 122}, {221, 222}, {321, 322}}