subset

When I try to remove the last row from a single column data frame, I get a vector back instead of a data frame: > df = data.frame(a=1:10) > df a 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 > df[-(length(df[,1])),] [1] 1 2 3 4 5 6 7 8 9 The behavior I'm looking for is what happens when I use this command on a two-column data frame: > df = data.frame(a=1:10,b=11:20) > df a b 1 1 11 2 2 12 3 3 13 4 4 14 5 5 15 6 6 16 7 7 17 8 8 18 9 9 19 10 10 20 > df[-(length(df[,1])),] a b 1 1 11 2 2 12 3 3 13 4 4 14 5 5 15 6 6 16 7 7 17 8 8 18 9 9 19 My code is general, and I don't know a priori whether the data

Let's say we have a Set S which contains a few subsets: - [a,b,c] - [a,b] - [c] - [d,e,f] - [d,f] - [e] Let's also say that S contains six unique elements: a, b, c, d, e and f . How can we find all possible subsets of S that contain each of the unique elements of S exactly once? The result of the function/method should be something like that: [[a,b,c], [d,e,f]]; [[a,b,c], [d,f], [e]]; [[a,b], [c], [d,e,f]]; [[a,b], [c], [d,f], [e]]. Is there any best practice or any standard way to achieve that? I would be grateful for a Pseudo-code, Ruby or Erlang example. It sounds like what you are looking

How can I easily check to see whether all the elements in one ArrayList are all elements of another ArrayList? Use Collection.containsAll() : boolean isSubset = listA.containsAll(listB); There is a containsAll method in all collections. 来源： https://stackoverflow.com/questions/808394/how-to-check-whether-the-elements-of-an-arraylist-are-all-contained-in-another-a

This question already has an answer here: Apply function conditionally 1 answer I looked online extensively and did not see an answer to this particular question (I think). The best way for me to explain myself will be with some code that replicates my problem. I made some temp data: x <- runif(100,1,2) y <- runif(100,2,3) z <- c(rep(1,100)) temp <- cbind(x,y,z) temp[1:25,3] = temp[1:25,3] +2 temp <- as.data.frame(temp) And this is what temp looks like x y z 1 1.512620 2.552271 3 2 1.133614 2.455296 3 3 1.543242 2.490120 3 4 1.047618 2.069474 3 . . . . . . . . 27 1.859012 2.687665 1 28 1

I want to test if an ordered set is a subset of a bigger ordered set. I used tuples and itertools.combinations : def subset_test(a, b): return a in itertools.combinations(b, len(a)) For instance, >>> subset_test((0, 1, 2), (0, 3, 1, 4, 2)) True >>> subset_test((0, 1, 2), (0, 3, 2, 4, 1)) False It works, but is slow when I test big tuples. You can simply use an iterator to keep track of the position in B >>> A = (0, 1, 2) >>> B = (0, 3, 1, 4, 2) >>> b_iter = iter(B) >>> all(a in b_iter for a in A) True Simple way of doing this >>> a = (0, 1, 2) >>> b = (0, 3, 1, 4, 2) >>> filter(set(a)._

This question already has an answer here: Check if an array is subset of another array in Ruby 4 answers Suppose I have the following Ruby code: array_1 = ['a', 'b'] array_2 = ['a', 'b', 'c'] some_function(array_1, array_2) # => True some_function(array_2, array_1) # => False some_function(['a', 'b'], ['a', 'd']) # => False some_function(['x', 'y'], array_2) # => False I am pretty much looking for some_function to return True when Parameter 2 contains all of the elements in Parameter 1. def f a,b (a-b).empty? end From a previous post, def f a,b (a-b).empty? end will not work the way you expect

I have a data frame of the following form: Temp Depth Light x time date time.at.depth 104 18.59 -2.7 27 21:38 2012-06-20 4 109 18.59 -2.7 27 22:02 2012-06-20 5 110 18.75 -4.0 27 22:07 2012-06-20 5 113 18.91 -2.7 27 22:21 2012-06-20 4 114 18.91 -4.0 27 22:26 2012-06-20 5 115 18.91 -2.7 27 22:31 2012-06-20 5 117 18.91 -2.7 27 22:40 2012-06-20 4 118 18.75 -4.0 27 22:45 2012-06-20 5 119 18.75 -2.7 27 22:50 2012-06-20 5 121 18.59 -4.0 27 22:59 2012-06-20 4 122 18.75 -2.7 27 23:04 2012-06-20 5 123 18.75 -4.0 27 23:09 2012-06-20 5 126 18.59 -2.7 27 23:23 2012-06-20 5 127 18.59 -2.7 27 23:28 2012-06