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Drop unused factor levels in a subsetted data frame
I have a data frame containing a factor . When I create a subset of this dataframe using subset or another indexing function, a new data frame is created. However, the factor variable retains all of its original levels, even when/if they do not exist in the new dataframe.
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console.log javascript [Function]
...will not be a window at all and console.log can always be expected. nodejs.org/api/stdio.html
– foiseworth
Apr 23 '14 at 19:42
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Capturing Groups From a Grep RegEx
...t even have to use grep:
files="*.jpg"
regex="[0-9]+_([a-z]+)_[0-9a-z]*"
for f in $files # unquoted in order to allow the glob to expand
do
if [[ $f =~ $regex ]]
then
name="${BASH_REMATCH[1]}"
echo "${name}.jpg" # concatenate strings
name="${name}.jpg" # sam...
What does it mean when git says a file “needs update”?
I can't for the life of me find any decent explanation of the "[file]: needs update" message that git sometimes spits out from time to time. Even the official git FAQ has explaining this marked as a TODO. If someone could explain A) what it means; and B) how to fix it, I would be extremely gratefu...
C++ compile error: has initializer but incomplete type
... file names by heart, which is a ridiculous expectation. I hope someone reports it as a bug.
– j riv
Jul 9 '18 at 11:07
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Regular expression to match standard 10 digit phone number
I want to write a regular expression for a standard US type phone number that supports the following formats:
20 Answers
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I want to execute shell commands from Maven's pom.xml
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Here's what's been working for me:
<plugin>
<artifactId>exec-maven-plugin</artifactId>
<groupId>org.codehaus.mojo</groupId>
<executions>
<execution><!-- Run our version calculation script -...
Where do you store your salt strings?
I've always used a proper per-entry salt string when hashing passwords for database storage. For my needs, storing the salt in the DB next to the hashed password has always worked fine.
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Running multiple TeamCity Agents on the same computer?
...talled on a single machine. They function as separate agents and TeamCity works with them as different agents, not utilizing the fact that they share the same machine.
After installing one agent you can install additional one, providing the following conditions are met:
the agents are installed in...
Find running median from a stream of integers
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There are a number of different solutions for finding running median from streamed data, I will briefly talk about them at the very end of the answer.
The question is about the details of the a specific solution (max heap/min heap solution), and how heap based solut...