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Drop unused factor levels in a subsetted data frame
...subsetting:
> subdf$letters
[1] a b c
Levels: a b c d e
subdf$letters <- factor(subdf$letters)
> subdf$letters
[1] a b c
Levels: a b c
EDIT
From the factor page example:
factor(ff) # drops the levels that do not occur
For dropping levels from all factor columns in a dataframe, y...
How do I upload a file with metadata using a REST web service?
... is that by the time the metadata exists, the content is already present. Ultimately the right answer depends on the organisation of the data in the system.
– Greg Hewgill
Oct 15 '10 at 3:09
...
Determine a string's encoding in C#
.../16/32 (bom, no bom, little & big endian)
Falls back to the local default codepage if no Unicode encoding was found.
Detects (with high probability) unicode files with the BOM/signature missing
Searches for charset=xyz and encoding=xyz inside file to help determine encoding.
To save processing, ...
How to call asynchronous method from synchronous method in C#?
...is calling async methods via async methods, but my whole program is not built with async methods.
15 Answers
...
What is the difference between MacVim and regular Vim?
...etter way to use MacVim's CLI executable in your shell is to move the mvim script bundled with MacVim somewhere in your $PATH and use this command:
$ mvim -v
EDIT: Yes, Terminal.app now supports 256 colors. So if you don't need iTerm2's advanced features you can safely use the default terminal em...
to_string is not a member of std, says g++ (mingw)
...
#include <string>
#include <sstream>
namespace patch
{
template < typename T > std::string to_string( const T& n )
{
std::ostringstream stm ;
stm << n ;
return stm.str() ;
...
Mapping two integers to one, in a unique and deterministic way
... : Z -> N, like so:
f(n) = n * 2 if n >= 0
f(n) = -n * 2 - 1 if n < 0
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Thymeleaf: how to use conditionals to dynamically add/remove a CSS class
...
There is also th:classappend.
<a href="" class="baseclass" th:classappend="${isAdmin} ? adminclass : userclass"></a>
If isAdmin is true, then this will result in:
<a href="" class="baseclass adminclass"></a>
...
Missing Maven dependencies in Eclipse project
...t of your eclipse's project.
2) Insert the following entry to the file:
<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
<attributes>
<attribute name="maven.pomderived" value="true"/>
<attribute name="org.eclipse.jst...
Returning IEnumerable vs. IQueryable
What is the difference between returning IQueryable<T> vs. IEnumerable<T> , when should one be preferred over the other?
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