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How can I create a correlation matrix in R?
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104
An example,
d &lt- data.frame(x1=rnorm(10),
x2=rnorm(10),
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What is the difference between Lisp-1 and Lisp-2?
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answered Jan 2 '11 at 14:52
pauldoopauldoo
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Selecting with complex criteria from pandas.DataFrame
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4 Answers
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How to swap keys and values in a hash
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edited Jan 14 at 0:20
the Tin Man
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How can I obtain the element-wise logical NOT of a pandas Series?
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274
To invert a boolean Series, use ~s:
In [7]: s = pd.Series([True, True, False, True])
In [8]: ~...
What is the difference between ~> and >= when specifying rubygem in Gemfile?
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edited Feb 5 '14 at 23:13
answered Nov 27 '10 at 17:33
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Bomb dropping algorithm
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edited Mar 9 '13 at 8:46
community wiki
4 r...
How can I create a Set of Sets in Python?
...m the following list of lists:
t = [[], [1, 2], [5], [1, 2, 5], [1, 2, 3, 4], [1, 2, 3, 6]]
you can create your set in the following way:
t1 = set(frozenset(i) for i in t)
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Python set to list
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245
Your code does work (tested with cpython 2.4, 2.5, 2.6, 2.7, 3.1 and 3.2):
>>> a = se...
Split delimited strings in a column and insert as new rows [duplicate]
... 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$V2, split = ",")
data.frame(V1 = rep(df$V1, sapply(s, length)), V2 = unlist(...