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Is R's apply family more than syntactic sugar?
... n < 2 ) n
+ else fibo(n-1) + fibo(n-2)
+ }
> system.time(for(i in 0:26) fibo(i))
user system elapsed
7.48 0.00 7.52
> system.time(sapply(0:26, fibo))
user system elapsed
7.50 0.00 7.54
> system.time(lapply(0:26, fibo))
user system elapsed
7.48 ...
What are best practices for validating email addresses on iOS 2.0
... the cleanest way to validate an email address that a user enters on iOS 2.0?
13 Answers
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C# Thread safe fast(est) counter
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answered Nov 1 '12 at 16:50
Austin SalonenAustin Salonen
44.8k1515 gold badges100100 silver badges134134 bronze badges
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How to generate a range of numbers between two numbers?
I have two numbers as input from the user, like for example 1000 and 1050 .
28 Answers
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Formatting floats without trailing zeros
...
Me, I'd do ('%f' % x).rstrip('0').rstrip('.') -- guarantees fixed-point formatting rather than scientific notation, etc etc. Yeah, not as slick and elegant as %g, but, it works (and I don't know how to force %g to never use scientific notation;-).
...
What is the GAC in .NET?
...s\assembly
C:\Windows\assembly>dir
Directory of C:\Windows\assembly
07/20/2009 02:18 PM <DIR> GAC
06/17/2009 04:22 PM <DIR> GAC_32
06/17/2009 04:22 PM <DIR> GAC_64
06/17/2009 04:22 PM <DIR> GAC_MSIL
...snip...
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Cleaning `Inf` values from an R dataframe
..., function(x) replace(x, is.infinite(x),NA))))
## user system elapsed
# 0.52 0.01 0.53
# is.na (@dwin)
system.time(is.na(dat) <- sapply(dat, is.infinite))
# user system elapsed
# 32.96 0.07 33.12
# modified is.na
system.time(is.na(dat) <- do.call(cbind,lapply(dat, is.infini...
Generate a random point within a circle (uniformly)
...andom point on BC. Ie. pick a pair of random numbers x and y uniformly on [0,R] giving distances from the center. Our triangle is a thin sliver so AB and BC are essentially parallel. So the point Z is simply a distance x+y from the origin. If x+y>R we fold back down.
Here's the complete algorith...
Store boolean value in SQLite
...rate Boolean storage class. Instead, Boolean values are stored as integers 0 (false) and 1 (true).
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