delete Null vector in list of vectors

Asked Jul 30 '18 at 16:46

Active Jul 30 '18 at 16:51

Viewed 22 times

if i have a list of vectors and one of them is null how i can delete it ,for example i have this list :

[[1]]
{(2, 5), (3, 6), (4, 5), (5, 2), (5, 4), (5, 7), (6, 3), (6, 7), (7, 5), (7, 6)}

[[2]]
{(1, 4), (3, 4), (3, 6), (4, 1), (4, 3), (4, 5), (4, 6), (4, 7), (4, 8), (5, 4), (6, 3),
 (6, 4), (6, 7), (7, 4), (7, 6), (8, 4)}

[[3]]
{(1, 8), (2, 5), (2, 8), (4, 5), (4, 8), (5, 2), (5, 4), (5, 7), (7, 5), (7, 8), (8, 1),
 (8, 2), (8, 4), (8, 7)}

[[4]]
NULL

[[5]]
{(1, 8), (3, 6), (6, 3), (6, 8), (8, 1), (8, 6)}

[[6]]
{(2, 5), (4, 5), (5, 2), (5, 4)}

[[7]]
NULL

[[8]]
NULL

so i want to delete the fourth the 7th and the 8th thanks

edited Jul 30 '18 at 16:48

duckmayr

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asked Jul 30 '18 at 16:46

ahmad alanaqreh

`x[lengths(x)>0]`? – r2evans Jul 30 '18 at 16:50
@RichScriven Yeah, the question I list above actually has essentially the same answer you suggest. – duckmayr Jul 30 '18 at 16:51
@r2evans - that may give incorrect results on list elements like `character(0)`, since it's length 0 but not NULL – Rich Scriven Jul 30 '18 at 16:51
1

good point, I was looking for the exception, thanks (I'll leave it up to preserve the "not-best solution and why") – r2evans Jul 30 '18 at 16:51
@RichScriven your function is working but the problem that i want to keep the index of the vectors and delete the Null ones – ahmad alanaqreh Jul 30 '18 at 16:57
You mean you want the indexes to be 1,2,3,5,6? Not possible. R adjusts the iindexes internally. – Rich Scriven Jul 30 '18 at 17:02

delete Null vector in list of vectors

0 Answers0