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Split delimited strings in a column and insert as new rows [duplicate]
...
Here is another way of doing it..
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 = rep(df...
Nearest neighbors in high-dimensional data?
...arching -- for music information retrieval.
You may be interested in Approximate Nearest Neighbor (ANN) algorithms. The idea is that you allow the algorithm to return sufficiently near neighbors (perhaps not the nearest neighbor); in doing so, you reduce complexity. You mentioned the kd-tree; that ...
What is the idiomatic Go equivalent of C's ternary operator?
... var+if+else block of code, though, this spelling is also used often:
index := val
if val <= 0 {
index = -val
}
and if you have a block of code that is repetitive enough, such as the equivalent of int value = a <= b ? a : b, you can create a function to hold it:
func min(a, b int) int ...
What's the 'Ruby way' to iterate over two arrays at once
More of a syntax curiosity than a problem to solve...
7 Answers
7
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How to get all possible combinations of a list’s elements?
... of elements from
the input iterable.
Combinations are emitted in lexicographic sort order. So, if the
input iterable is sorted, the
combination tuples will be produced in
sorted order.
Since 2.6, batteries are included!
...
How do I find all of the symlinks in a directory tree?
...fact the find man page says:
-L Follow symbolic links. When find examines or prints information
about files, the information used shall be taken from the prop‐
erties of the file to which the link points, not from the link
itself (unless it is a broken sym...
What code analysis tools do you use for your Java projects? [closed]
...he PMD web page.
I'd like to point out that these tools can sometimes be extended beyond their "out-of-the-box" set of rules. And not just because they're open source so that you can rewrite them. Some of these tools come with applications or "hooks" that allow them to be extended. For example, PMD...
How can I concatenate regex literals in JavaScript?
...
Here is how to create a regular expression without using the regular expression literal syntax. This lets you do arbitary string manipulation before it becomes a regular expression object:
var segment_part = "some bit of the regexp";
var pattern = new RegEx...
How can I read a function's signature including default argument values?
Given a function object, how can I get its signature? For example, for:
8 Answers
8
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Is there a documented way to set the iPhone orientation?
...s. I personally have been told by Apple to remove the method call on my next update so I am not yet sure if having a hack for older devices will get through the approval process.
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