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Can dplyr package be used for conditional mutating?
...x) sample(7, 1e7, TRUE)))
setnames(DT, letters[1:6])
# > dim(DT)
# [1] 10000000 6
DF <- as.data.frame(DT)
DT_fun <- function(DT) {
DT[(a %in% c(0,1,3,4) | c == 4), g := 3L]
DT[a %in% c(2,5,7) | (a==1 & b==4), g := 2L]
}
DPLYR_fun <- function(DF) {
mutate(DF, g =...
What is the difference between svg's x and dx attribute?
...eight', 500);
svg.append("line").attr('x1', 0).attr('x2', 500).attr('y1', 100).attr('y2', 100);
svg.append("line").attr('x1', 0).attr('x2', 500).attr('y1', 200).attr('y2', 200);
group = svg.selectAll("g")
.data(dataset)
.enter()
.append("g");
// Without the dy=0.35em offset
group.appe...
CSS endless rotation animation
...ting 2s linear infinite;
}
<div
class="rotating"
style="width: 100px; height: 100px; line-height: 100px; text-align: center;"
>Rotate</div>
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...
How can I be notified when an element is added to the page?
... solution than the one presented here. Seriously. Don't poll the DOM every 100 milliseconds; it will waste CPU power and your users will hate you.
Since mutation events were deprecated in 2012, and you have no control over the inserted elements because they are added by someone else's code, your on...
Fixed point vs Floating point number
... For example, I might want to keep two digits of precision, so a value of 100 means actually means 1.00, 101 means 1.01, 12345 means 123.45, etc.
Floating point numbers are more general purpose because they can represent very small or very large numbers in the same way, but there is a small penalt...
JavaScript variables declare outside or inside loop?
...ou've got yourself an accidental global.
In particular:
for (var i; i<100; i++)
do something;
for (var i; i<100; i++)
do something else;
Crockford will recommend you remove the second var (or remove both vars and do var i; above), and jslint will whinge at you for this. But IMO it...
Should I use char** argv or char* argv[]?
...
char* argv[] is 100% equivalent to char** argv when used as a parameter type of a function. no "const" involved, also not implicitly. Both are pointers to pointers to characters. It's different in regard to what you declare. But the compiler...
How to generate a random int in C?
...till find that confusing, try writing a program that has i count from 0 to 100, and prints out i % n for some n of your choosing smaller than 100.
– Laurence Gonsalves
Aug 14 '14 at 23:52
...
How do I make an asynchronous GET request in PHP?
...timeout). The best you can do is to set a low timeout on fsockopen to 0.1 (100ms) and $my_timeout to 100ms. You risk though, that the request timeout.
– Chris Cinelli
Oct 25 '12 at 0:53
...
How to detect shake event with android?
...g curTime = System.currentTimeMillis();
// only allow one update every 100ms.
if ((curTime - lastUpdate) > 100) {
long diffTime = (curTime - lastUpdate);
lastUpdate = curTime;
x = values[SensorManager.DATA_X];
y = values[SensorManager.DATA_Y];
z = values[Sen...