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What is the difference between RDF and OWL? [closed]
I am trying to grasp the concept of Semantic Web. I am finding it hard to understand what exactly is the difference between RDF and OWL. Is OWL an extension of RDF or these two are totally different technologies?
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How do you delete a column by name in data.table?
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Any of the following will remove column foo from the data.table df3:
# Method 1 (and preferred as it takes 0.00s even on a 20GB data.table)
df3[,foo:=NULL]
df3[, c("foo","bar"):=NULL] # remove two columns
myVar = "foo"
df3[, (myVar):=NULL] # lookup myVar contents
# Method 2a --...
Pandas aggregate count distinct
...user activity and I want to generate a report of total duration and the number of unique users per day.
3 Answers
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Which is faster : if (bool) or if(int)?
The above topic made me do some experiments with bool and int in if condition. So just out of curiosity I wrote this program:
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Why does the use of 'new' cause memory leaks?
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What is happening
When you write T t; you're creating an object of type T with automatic storage duration. It will get cleaned up automatically when it goes out of scope.
When you write new T() you're creating an object of type T with dynamic storage duration. It won't get cleaned ...
What are Aggregates and PODs and how/why are they special?
This FAQ is about Aggregates and PODs and covers the following material:
6 Answers
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pandas: How do I split text in a column into multiple rows?
...file and the next to last column has a string of text that I want to split by a specific delimiter. I was wondering if there is a simple way to do this using pandas or python?
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What is the “FS”/“GS” register intended for?
So I know what the following registers and their uses are supposed to be:
5 Answers
5
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psql invalid command \N while restore sql
I'm trying to restore my dump file, but it caused an error:
12 Answers
12
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Why do we need extern “C”{ #include } in C++?
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C and C++ are superficially similar, but each compiles into a very different set of code. When you include a header file with a C++ compiler, the compiler is expecting C++ code. If, however, it is a C header, then the compiler expects the data contained in the h...