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“use database_name” command in PostgreSQL
... testdatabase
At this point you might see the following output
You are now connected to database "testdatabase" as user "user_name".
testdatabase=#
Notice how the prompt changes. Cheers, have just been hustling looking for this too, too little information on postgreSQL compared to MySQL and th...
Calling Java varargs method with single null argument?
...
The issue is that when you use the literal null, Java doesn't know what type it is supposed to be. It could be a null Object, or it could be a null Object array. For a single argument it assumes the latter.
You have two choices. Cast the null explicitly to Object or call the method u...
How to pretty-print a numpy.array without scientific notation and with given precision?
...ent zeros from being stripped from the end of floats:
np.set_printoptions now has a formatter parameter which allows you to specify a format function for each type.
np.set_printoptions(formatter={'float': '{: 0.3f}'.format})
print(x)
which prints
[ 0.078 0.480 0.413 0.830 0.776 0.102 0.51...
How can I make an svg scale with its parent container?
...0 10,0" />
</svg>
It will render as a 10px by 20px triangle:
Now, if you set only the width and height, that will change the size of the SVG element, but not scale the triangle:
<svg width=100 height=50>
<polygon fill=red stroke-width=0
points="0,10 20,10 10...
Regex for splitting a string using space when not surrounded by single or double quotes
... them. I'll leave that as an exercise for the reader or another poster for now, as 2am is way too late to be messing with regular expressions anymore ;)
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IPC performance: Named Pipe vs Socket
...urely trying to optimize something that isn't yet problematic. Unless you know sockets are going to be a bottleneck, I'd just use them.
A lot of people who swear by named pipes find a little savings (depending on how well everything else is written), but end up with code that spends more time block...
How to break out or exit a method in Java?
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Will this work for exiting from a constructor? I know it's a bit strange but I need this hack.
– stillanoob
Oct 21 '16 at 12:35
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Javascript call() & apply() vs bind()?
I already know that apply and call are similar functions which set this (context of a function).
22 Answers
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Remove duplicated rows using dplyr
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Note: dplyr now contains the distinct function for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One appr...
How can I round up the time to the nearest X minutes?
...ldDateTimeObject.Minute % 15);
}
and is called like that
DateTime thisIsNow = DateTime.Now;
DateTime nextQuarterHour = GetNextQuarterHour(thisIsNow);
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