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Draw a perfect circle from user's touch
...port java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.HeadlessException;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util....
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
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26
Since dplyr 0.8 group_by gained the .drop argument that does just what you asked for:
df = dat...
How to remove item from list in C#?
... use Remove(T item):
var itemToRemove = resultlist.Single(r => r.Id == 2);
resultList.Remove(itemToRemove);
When you are not sure the item really exists you can use SingleOrDefault. SingleOrDefault will return null if there is no item (Single will throw an exception when it can't find the item...
How to detect a Christmas Tree? [closed]
... is just a simple monochrome brightness test; any pixels with values above 220 on a 0-255 scale (where black is 0 and white is 255) are saved to a binary black-and-white image. The second threshold tries to look for red and yellow lights, which are particularly prominent in the trees in the upper l...
ArithmeticException: “Non-terminating decimal expansion; no exact representable decimal result”
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862
From the Java 11 BigDecimal docs:
When a MathContext object is supplied with a precision settin...
Scala how can I count the number of occurrences in a list
I want to implement it like this: list.count(2) (returns 3).
16 Answers
16
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How to store standard error in a variable
...d output.
ERROR=$( { ./useless.sh | sed s/Output/Useless/ > outfile; } 2>&1 )
Note that the semi-colon is needed (in classic shells - Bourne, Korn - for sure; probably in Bash too). The '{}' does I/O redirection over the enclosed commands. As written, it would capture errors from sed ...
Regular expression to match any character being repeated more than 10 times
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edited Jun 22 '16 at 17:52
Wiktor Stribiżew
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How to subtract 2 hours from user's local time?
...e JavaScript code block that will allow me to display the local time minus 2 hours?
2 Answers
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