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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
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Since dplyr 0.8 group_by gained the .drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a)...
Editing dictionary values in a foreach loop
... double percent = colStates[key] / TotalCount;
if (percent < 0.05)
{
OtherCount += colStates[key];
colStates[key] = 0;
}
}
Or...
Creating a list of modifications
List<string> keysToNuke = new List<string>();
foreach(string key in colStates.Keys)
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~x + ~y == ~(x + y) is always false?
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edited Jun 20 '12 at 13:47
answered Jun 20 '12 at 2:35
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ActiveRecord: size vs count
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edited Jul 10 '12 at 22:15
Jo Liss
22.5k1414 gold badges101101 silver badges150150 bronze badges
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How do I round to the nearest 0.5?
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208
Multiply your rating by 2, then round using Math.Round(rating, MidpointRounding.AwayFromZero), ...
How to open, read, and write from serial port in C?
...ity)
{
struct termios tty;
if (tcgetattr (fd, &tty) != 0)
{
error_message ("error %d from tcgetattr", errno);
return -1;
}
cfsetospeed (&tty, speed);
cfsetispeed (&tty, speed);
tty.c_cflag = (tty.c_...
What does it mean when an HTTP request returns status code 0?
...r any other type of HTTP network request, fail with an HTTP status code of 0?
15 Answers
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Catching error codes in a shell pipe
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20
If you really don't want the second command to proceed until the first is known to be successful...
How to configure PostgreSQL to accept all incoming connections
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Just use 0.0.0.0/0.
host all all 0.0.0.0/0 md5
Make sure the listen_addresses in postgresql.conf (or ALTER SYSTEM SET) allows incoming connections on all available IP interfaces.
listen_addres...
What does multicore assembly language look like?
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10 Answers
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