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Print all but the first three columns
...s",$i OFS; if(NF) printf "%s",$NF; printf ORS}'
### Example ###
$ echo '1 2 3 4 5 6 7' |
awk '{for(i=4;i<NF;i++)printf"%s",$i OFS;if(NF)printf"%s",$NF;printf ORS}' |
tr ' ' '-'
4-5-6-7
Sudo_O proposes an elegant improvement using the ternary operator NF?ORS:OFS
$ echo '1 2 3 4 5 6 7' |
...
How do I make a list of data frames?
... function call. If you use <-, you'll end up creating variables y1 and y2 in whatever environment you're working in:
d1 <- data.frame(y1 <- c(1, 2, 3), y2 <- c(4, 5, 6))
y1
# [1] 1 2 3
y2
# [1] 4 5 6
This won't have the seemingly desired effect of creating column names in the data fra...
What is Weak Head Normal Form?
...ains no un-evaluated thunks).
These expressions are all in normal form:
42
(2, "hello")
\x -> (x + 1)
These expressions are not in normal form:
1 + 2 -- we could evaluate this to 3
(\x -> x + 1) 2 -- we could apply the function
"he" ++ "llo" -- we could apply...
Assign multiple columns using := in data.table, by group
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2 Answers
2
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What is the ultimate postal code and zip regex?
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20 Answers
20
Active
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For each row return the column name of the largest value
...d() to make examples using sample reproducible):
DF <- data.frame(V1=c(2,8,1),V2=c(7,3,5),V3=c(9,6,4))
colnames(DF)[apply(DF,1,which.max)]
[1] "V3" "V1" "V2"
A faster solution than using apply might be max.col:
colnames(DF)[max.col(DF,ties.method="first")]
#[1] "V3" "V1" "V2"
...where ties...
How to convert list of tuples to multiple lists?
...lt-in function zip() will almost do what you want:
>>> zip(*[(1, 2), (3, 4), (5, 6)])
[(1, 3, 5), (2, 4, 6)]
The only difference is that you get tuples instead of lists. You can convert them to lists using
map(list, zip(*[(1, 2), (3, 4), (5, 6)]))
...
How to select rows from a DataFrame based on column values?
... three'.split(),
'C': np.arange(8), 'D': np.arange(8) * 2})
print(df)
# A B C D
# 0 foo one 0 0
# 1 bar one 1 2
# 2 foo two 2 4
# 3 bar three 3 6
# 4 foo two 4 8
# 5 bar two 5 10
# 6 foo one 6 12
# 7 foo three 7 14
pri...
How can I plot with 2 different y-axes?
...that each set of points has its own (different) y-axis (i.e., in positions 2 and 4 on the figure) but the points appear superimposed on the same figure.
...
How to return a part of an array in Ruby?
...ndex) are out of range.
a = [ "a", "b", "c", "d", "e" ]
a[2] + a[0] + a[1] #=> "cab"
a[6] #=> nil
a[1, 2] #=> [ "b", "c" ]
a[1..3] #=> [ "b", "c", "d" ]
a[4..7] #=> [ "e...