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Check if a number is int or float
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edited Dec 27 '10 at 20:00
answered Dec 27 '10 at 19:16
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More than 10 lines in a node.js stack error?
Is there a way to get more than 10 lines in a node.js stack error?
4 Answers
4
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Remove duplicated rows using dplyr
...ow:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [...
Should one use < or
... the loop.
– Jon Skeet
Apr 2 '09 at 10:22
5
Generic programming with STL iterators mandates use o...
How to configure Eclipse build path to use Maven dependencies?
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answered Jan 10 '10 at 14:11
BuhbBuhb
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IN vs OR in the SQL WHERE Clause
...h your specific data to see which is faster.
I tried both on a MySQL with 1000000 rows. When the column is indexed there is no discernable difference in performance - both are nearly instant. When the column is not indexed I got these results:
SELECT COUNT(*) FROM t_inner WHERE val IN (1000, 2000,...
Scala @ operator
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answered Mar 1 '10 at 21:56
Daniel C. SobralDaniel C. Sobral
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HashSet versus Dictionary w.r.t searching time to find if an item exists
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HashSet vs List vs Dictionary performance test, taken from here.
Add 1000000 objects (without checking duplicates)
Contains check for half the objects of a collection of 10000
Remove half the objects of a collection of 10000
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Is MonoTouch now banned on the iPhone? [closed]
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answered Apr 8 '10 at 23:11
Lance McNearneyLance McNearney
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In Python, how do you convert a `datetime` object to seconds?
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