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Drop data frame columns by name
...st of names :
DF <- data.frame(
x=1:10,
y=10:1,
z=rep(5,10),
a=11:20
)
drops <- c("x","z")
DF[ , !(names(DF) %in% drops)]
Or, alternatively, you can make a list of those to keep and refer to them by name :
keeps <- c("y", "a")
DF[keeps]
EDIT :
For those still not acquainted wi...
round() doesn't seem to be rounding properly
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answered Sep 11 '08 at 15:11
JimmyJimmy
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Why do x86-64 systems have only a 48 bit virtual address space?
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answered Jul 16 '11 at 11:16
jalfjalf
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Incrementing a date in JavaScript
...te object is smart about rollover:
var lastDayOf2015 = new Date(2015, 11, 31);
snippet.log("Last day of 2015: " + lastDayOf2015.toISOString());
var nextDay = new Date(+lastDayOf2015);
var dateValue = nextDay.getDate() + 1;
snippet.log("Setting the 'date' part to " + dateValue);
nextDay.set...
Can I change all my http:// links to just //?
...
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edited Jan 28 '11 at 19:15
answered Jan 28 '11 at 19:04
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Why use String.Format? [duplicate]
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answered Jan 12 '11 at 17:07
Moo-JuiceMoo-Juice
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How do shift operators work in Java? [duplicate]
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System.out.println(Integer.toBinaryString(2 << 11));
Shifts binary 2(10) by 11 times to the left. Hence: 1000000000000
System.out.println(Integer.toBinaryString(2 << 22));
Shifts binary 2(10) by 22 times to the left. Hence : 100000000000000000000000
System.o...
fastest MD5 Implementation in JavaScript
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Matt BakerMatt Baker
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Remove trailing zeros
... |
edited May 23 '17 at 11:47
Community♦
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answered Dec 24 '10 at 11:14
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What is the official “preferred” way to install pip and virtualenv systemwide?
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answered Jul 11 '13 at 18:53
Tal WeissTal Weiss
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