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Summarizing multiple columns with dplyr? [duplicate]
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The dplyr package contains summarise_all for this aim:
library(dplyr)
df %>% group_by(grp) %>% summarise_all(list(mean))
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#>...
OS X: equivalent of Linux's wget
...p;& make -j8 && make install
Or, use a bash alias:
function _wget() { curl "${1}" -o $(basename "${1}") ; };
alias wget='_wget'
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What are the options for storing hierarchical data in a relational database? [closed]
...s a result, most people end up having to settle for one or the other especially if there are more than, say, a lousy 100,000 nodes or so. Using the push stack method can take a whole day to do the conversion on what MLM'ers would consider to be a small million node hierarchy.
I thought I'd give Ce...
Where are iOS simulator screenshots stored?
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For me, there's nothing in that folder. It's all on the Desktop. Not sure why? :/
– chakrit
Feb 9 '12 at 6:21
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Load local JSON file into variable
...nts:queue"
},
{
"id": "0.79281",
"name": " contents:mqq_error"
}
]
}
You also had an extra }.
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Get list of passed arguments in Windows batch script (.bat)
...ke to find a Windows batch counterpart to Bash's $@ that holds a list of all arguments passed into a script.
14 Answers
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Not equal != operator on NULL
...dicates for such situations.
This behavior is not specific to SQL Server. All standards-compliant SQL dialects work the same way.
Note: To compare if your value is not null, you use IS NOT NULL, while to compare with not null value, you use <> 'YOUR_VALUE'. I can't say if my value equals or ...
What's onCreate(Bundle savedInstanceState)
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If you save the state of the application in a bundle (typically non-persistent, dynamic data in onSaveInstanceState), it can be passed back to onCreate if the activity needs to be recreated (e.g., orientation change) so that you don't lose this prior information. If no data was suppl...
How to read multiple text files into a single RDD?
... RDD. The API here is just an exposure of Hadoop's FileInputFormat API, so all the same Path options apply.
– Nick Chammas
Jun 4 '14 at 15:04
7
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MAC addresses in JavaScript
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I concur with all the previous answers that it would be a privacy/security vulnerability if you would be able to do this directly from Javascript. There are two things I can think of:
Using Java (with a signed applet)
Using signed Javasc...