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Extracting specific columns from a data frame
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Using the dplyr package, if your data.frame is called df1:
library(dplyr)
df1 %>%
select(A, B, E)
This can also be written without the %>% pipe as:
select(df1, A, B, E)
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What's the difference between UTF-8 and UTF-8 without BOM?
...OM or where the BOM is used as a UTF-8 signature. See the “Byte Order Mark” subsection in Section 16.8, Specials, for more information.
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How to reset AUTO_INCREMENT in MySQL?
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NielsNiels
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How can I replace a newline (\n) using sed?
...ch is the whole file).
Here is cross-platform compatible syntax which works with BSD and OS X's sed (as per @Benjie comment):
sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g' file
As you can see, using sed for this otherwise simple problem is problematic. For a simpler and adequate solution see this ...
Inserting a tab character into text using C#
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SteveC
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answered Dec 14 '08 at 3:25
DShookDShook
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What is a covariant return type?
...od which holds an explicit reference to a MyFoo object will be able to invoke clone() and know (without casting) that the return value is an instance of MyFoo. Without covariant return types, the overridden method in MyFoo would have to be declared to return Object - and so calling code would have ...
Remove stubborn underline from link
I am attempting to have a link show up in white, without an underline. The text color shows up correctly as white, but the blue underline is stubbornly persisting. I tried text-decoration: none; and text-decoration: none !important; in the CSS to remove the link underline. Neither worked.
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Loop through a date range with JavaScript
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Here's a way to do it by making use of the way adding one day causes the date to roll over to the next month if necessary, and without messing around with milliseconds. Daylight savings aren't an issue either.
var now = new Date();
var daysOfYear = []...
Mercurial: how to amend the last commit?
I'm looking for a counter-part of git commit --amend in Mercurial, i.e. a way to modify the commit which my working copy is linked to. I'm only interested in the last commit, not an arbitrary earlier commit.
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What is the difference between substr and substring?
...e), but the second argument to substr is the maximum length to return.
Links?
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substr
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring
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