2
$\begingroup$

Gday guys. This problem troubles me, and I hope you can help me solve it.

Say I have two random lists 

L1={{2},{5},{1},{0},{4},{7},{8}}
L2={2,5,1,0,4,7,8}

and also a list

L3={3,5}

the list L3 means I don't want the elements in L1 at row 3 and 5, and elements in L2 at column 3 and 5. So I would like the results to come up like

resultsL1={{2},{5},{0},{7},{8}}
resultsL2={2,5,0,7,8}

I know how to use Delete or Drop to get rid of the row/column one by one, but I want an automatic way to do this job because the elements in L3 can have different elements and become any number in my original code. Thanks in advance!!

Improve this question
$\endgroup$
1
  • $\begingroup$ Also see: (43785) $\endgroup$
    – Mr.Wizard
    Feb 5, 2015 at 10:41

2 Answers 2

Reset to default
2
$\begingroup$

There are several ways but the one I like is the following:

If L1 and L2 have same length then:

index = Complement[Range[Length[L1]], L3];
L1[[index]]
(*{{2}, {5}, {0}, {7}, {8}}*)
L2[[index]]
(*{2, 5, 0, 7, 8}*)
Improve this answer
$\endgroup$
2
  • $\begingroup$ Thank you Algohi. It works perfectly! $\endgroup$
    – user11726
    Feb 5, 2015 at 3:40
  • $\begingroup$ My pleasure :). $\endgroup$
    – Basheer Algohi
    Feb 5, 2015 at 3:47
2
$\begingroup$

Try this:

    Delete[L1, {#} & /@ L3]
Delete[L2, {#} & /@ L3]

(*  {{2}, {5}, {0}, {7}, {8}}  *)

(*   {2, 5, 0, 7, 8}          *)

Have fun!

Improve this answer
$\endgroup$
1
  • $\begingroup$ Nice! Thanks Alexi! $\endgroup$
    – user11726
    Feb 6, 2015 at 6:47

Not the answer you're looking for? Browse other questions tagged or ask your own question.