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Setting JDK in Eclipse
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146
You manage the list of available compilers in the Window -> Preferences -> Java -> In...
How to sleep for five seconds in a batch file/cmd [duplicate]
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One hack is to (mis)use the ping command:
ping 127.0.0.1 -n 6 > nul
Explanation:
ping is a system utility that sends ping requests. ping is available on all versions of Windows.
127.0.0.1 is the IP address of localhost. This IP address is guaranteed to always resol...
Easy way to test a URL for 404 in PHP?
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15 Answers
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Truncating floats in Python
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117
First, the function, for those who just want some copy-and-paste code:
def truncate(f, n):
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What does .SD stand for in data.table in R
...his is your data.table:
DT = data.table(x=rep(c("a","b","c"),each=2), y=c(1,3), v=1:6)
setkey(DT, y)
DT
# x y v
# 1: a 1 1
# 2: b 1 3
# 3: c 1 5
# 4: a 3 2
# 5: b 3 4
# 6: c 3 6
Doing this may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1...
When is memoization automatic in GHC Haskell?
I can't figure out why m1 is apparently memoized while m2 is not in the following:
4 Answers
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What is IP address '::1'?
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152
::1 is the loopback address in IPv6. Think of it as the IPv6 version of 127.0.0.1.
See http:...
SQL Server dynamic PIVOT query?
...me,
category varchar(3),
amount money
)
insert into temp values ('1/1/2012', 'ABC', 1000.00)
insert into temp values ('2/1/2012', 'DEF', 500.00)
insert into temp values ('2/1/2012', 'GHI', 800.00)
insert into temp values ('2/10/2012', 'DEF', 700.00)
insert into temp values ('3/1/2012', 'ABC...
Sql Server equivalent of a COUNTIF aggregate function
...ondition (e.g. count only records where a certain column value is equal to 1).
9 Answers
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How do you create a yes/no boolean field in SQL server?
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11 Answers
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