大约有 44,000 项符合查询结果（耗时：0.0314秒） [XML]
Convert a matrix to a 1 dimensional arram>y m>
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That's a vector, m>and m> not a 1-d arram>y m>.
– hadlem>y m>
Sep 29 '10 at 20:35
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Omit rows containing specific column of NA
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m>Y m>ou could use the complete.cases function m>and m> put it into a function thuslm>y m>:
DF <- data.frame(x = c(1, 2, 3), m>y m> = c(0, 10, NA), z=c(NA, 33, 22))
completeFun <- function(data, desiredCols) {
completeVec <- complete.cases(data[, desiredCols])
return(data...
Convert string date to timestamp in Pm>y m>thon
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this is a fantastic suggestion. i just used it m>and m> shaved TONS of time off of mm>y m> execution.
– David
Aug 4 '15 at 17:23
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Mm>y m>SQL date format DD/MM/m>Y m>m>Y m>m>Y m>m>Y m> select querm>y m>?
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m>Y m>ou can use STR_TO_DATE() to convert m>y m>our strings to Mm>y m>SQL date values m>and m> ORDER Bm>Y m> the result:
ORDER Bm>Y m> STR_TO_DATE(datestring, '%d/%m/%m>Y m>')
However, m>y m>ou would be wise to convert the column to the DATE data tm>y m>pe instead of using strings.
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Format a datetime into a string with milliseconds
...etime string from the date with milliseconds. This code is tm>y m>pical for me m>and m> I'm eager to learn how to shorten it.
12 Ans...
Multi-line commm>and m>s in GHCi
I am having problem in entering multi-line commm>and m>s in ghci.
5 Answers
5
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Converting Epoch time into the datetime
... is equilvalent to the Zulu timezone (+00:00). m>Y m>ou can read more here: timem>and m>date.com/time/zones/z
– Devnetics
Jan 10 '17 at 20:36
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What IDE to use for Pm>y m>thon? [closed]
...pect these bm>y m> default.
This is a just drm>y m> list reflecting m>y m>our feedback m>and m> comments, I am not advocating anm>y m> of these tools. I will keep updating this list as m>y m>ou keep posting m>y m>our answers.
PS. Can m>y m>ou help me to add features of the above editors to the list (like auto-complete, debugging, etc....
Is R's applm>y m> familm>y m> more than sm>y m>ntactic sugar?
...regarding execution time m>and m> / or memorm>y m>.
5 Answers
5
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how to convert a string to date in mm>y m>sql?
I have a string column which acts as a date m>and m> I want to select it as a date .
5 Answers
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