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Should I use a data.frame or a matrix?
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Something not mentioned by @Michal is that not only is a matrix smaller than the equivalent data frame, using matrices can make your code far more efficient than using data frames, often considerably so. That is one reason why internally, a lot of R functions will coerce to matrices data th...
Find all storage devices attached to a Linux machine [closed]
I have a need to find all of the writable storage devices attached to a given machine, whether or not they are mounted.
7...
In C#, can a class inherit from another class and an interface?
...develop a generic component/interface that I can use to write programs for all our devices that will help keep the common things (like connecting, disconnecting, getting firmware) the same for all of our applications.
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Laravel Check If Related Model Exists
...hp 7.2+ you can't use count on the relation object, so there's no one-fits-all method for all relations. Use query method instead as @tremby provided below:
$model->relation()->exists()
generic solution working on all the relation types (pre php 7.2):
if (count($model->relation))
{
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What are the differences between double-dot “..” and triple-dot “…” in Git commit ranges?
...t
can be written as "r1..r2".
A similar notation "r1...r2" is
called symmetric difference of r1 and
r2 and is defined as "r1 r2 --not
$(git merge-base --all r1 r2)". It is
the set of commits that are
reachable from either one of r1 or r2
but not from both.
Which basical...
What is the difference between Bower and npm?
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All package managers have many downsides. You just have to pick which you can live with.
History
npm started out managing node.js modules (that's why packages go into node_modules by default), but it works for the front-end...
Javascript Array of Functions
...help others (like me 20 minutes ago :-) looking for any hint about how to call JS functions in an array.
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...e to go with @Moody_Mudskipper's answer: Using .drop=FALSE can give potentially unexpected results when one or more grouping variables are not coded as factors. See examples below:
library(dplyr)
data(iris)
# Add an additional level to Species
iris$Species = factor(iris$Species, levels=c(levels(ir...
image processing to improve tesseract OCR accuracy
... highly pixellated - for example that generated by fax machines - is especially difficult for tesseract to process - presumably all those jagged edges to the characters confound the shape-recognition algorithms.
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How to define servlet filter order of execution using annotations in WAR
...ation. However, to minimize the web.xml usage, it's sufficient to annotate all filters with just a filterName so that you don't need the <filter> definition, but just a <filter-mapping> definition in the desired order.
For example,
@WebFilter(filterName="filter1")
public class Filter1 ...