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Relative frequencies / proportions with dplyr
...se(n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That mak...
Best way to make Java's modulus behave like it should with negative numbers?
...
144
It behaves as it should a % b = a - a / b * b; i.e. it's the remainder.
You can do (a % b + b...
How do I verify that an Android apk is signed with a release certificate?
...
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edited Jan 27 '17 at 20:05
Eugene
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answ...
Why does Decimal.Divide(int, int) work, but not (int / int)?
...
219
int is an integer type; dividing two ints performs an integer division, i.e. the fractional par...
Regex how to match an optional character
...
Use
[A-Z]?
to make the letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-...
CSS filter: make color image with transparency white
...
You can use
filter: brightness(0) invert(1);
html {
background: red;
}
p {
float: left;
max-width: 50%;
text-align: center;
}
img {
display: block;
max-width: 100%;
}
.filter {
-webkit-filter: brightness(0) invert(1);
filter: brig...
How to determine if a point is in a 2D triangle? [closed]
...nce issues.
And here's some code to get you started:
float sign (fPoint p1, fPoint p2, fPoint p3)
{
return (p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y);
}
bool PointInTriangle (fPoint pt, fPoint v1, fPoint v2, fPoint v3)
{
float d1, d2, d3;
bool has_neg, has_pos;
...
Redirect STDERR / STDOUT of a process AFTER it's been started, using command line?
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126
Short of closing and reopening your tty (i.e. logging off and back on, which may also terminat...
Remote Connections Mysql Ubuntu
...ld come back something like this with your actual IP in the xxx's
mysqld 1046 mysql 10u IPv4 5203 0t0 TCP xxx.xxx.xxx.xxx:3306 (LISTEN)
If the above statement returns correctly you will then be able to accept remote users. However for a remote user to connect with the correct priveleges y...