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Why can't R's ifelse statements return vectors?
I've found R's ifelse statements to be pretty handy from time to time. For example:
9 Answers
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Count work days between two dates
...ET @StartDate = '2008/10/01'
SET @EndDate = '2008/10/31'
SELECT
(DATEDIFF(dd, @StartDate, @EndDate) + 1)
-(DATEDIFF(wk, @StartDate, @EndDate) * 2)
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)
-(CASE WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN 1 ELSE 0 END)
If you...
What is the most efficient way of finding all the factors of a number in Python?
...st.__add__,
([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0)))
This will return all of the factors, very quickly, of a number n.
Why square root as the upper limit?
sqrt(x) * sqrt(x) = x. So if the two factors are the same, they're both the square root. If you make o...
Check if the number is integer
... was surprised to learn that R doesn't come with a handy function to check if the number is integer.
12 Answers
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How to export all data from table to an insertable sql format?
...es like this generate to a new query editor window and then just do any modifications where needed.
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Procedure expects parameter which was not supplied
...
In addition to the other answers here, if you've forgotten to put:
cmd.CommandType = CommandType.StoredProcedure;
Then you will also get this error.
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How to create the most compact mapping n → isprime(n) up to a limit N?
...the primality test.
There isn't really a data structure for you to query. If you have lots of numbers to test, you should probably run a probabilistic test since those are faster, and then follow it up with a deterministic test to make sure the number is prime.
You should know that the math behind...
Simple C example of doing an HTTP POST and consuming the response
...sage body separated by a blank line. The blank line is ALWAYS needed even if there is no message body. The header starts with a command and has additional lines of key value pairs separated by a colon and a space. If there is a message body, it can be anything you want it to be.
Lines in the hea...
Logical operators (“and”, “or”) in DOS batch
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You can do and with nested conditions:
if %age% geq 2 (
if %age% leq 12 (
set class=child
)
)
or:
if %age% geq 2 if %age% leq 12 set class=child
You can do or with a separate variable:
set res=F
if %hour% leq 6 set res=T
if %hour% geq 22 set ...
Meaning of “[: too many arguments” error from if [] (square brackets)
...
If your $VARIABLE is a string containing spaces or other special characters, and single square brackets are used (which is a shortcut for the test command), then the string may be split out into multiple words. Each of these ...