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Define all functions in one .R file, call them from another .R file. How, if possible?
...") (assuming that both these files are in your current working directory.
If abc.R is:
fooABC <- function(x) {
k <- x+1
return(k)
}
and xyz.R is:
fooXYZ <- function(x) {
k <- fooABC(x)+1
return(k)
}
then this will work:
> source("abc.R")
> source("xyz.R")
&g...
Quicksort: Choosing the pivot
...e middle element would also be acceptable in the majority of cases.
Also, if you are implementing this yourself, there are versions of the algorithm that work in-place (i.e. without creating two new lists and then concatenating them).
...
How do I put an 'if clause' in an SQL string?
...
For your specific query, you can do:
UPDATE purchaseOrder
SET purchaseOrder_status = 'COMPLETED'
WHERE purchaseOrder_ID = '@purchaseOrder_ID' and
not exists (SELECT *
FROM itemsOrdered WHERE purcha...
Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath:
...
You're using the dequeueReusableCellWithIdentifier:forIndexPath: method. The documentation for that method says this:
Important: You must register a class or nib file using the registerNib:forCellReuseIdentifier: or registerClass:forCellReuseIdentifier: method befo...
mongoDB/mongoose: unique if not null
I was wondering if there is way to force a unique collection entry but only if entry is not null .
e
Sample schema:
4 Answ...
What are static factory methods?
...o we use a static factory method getDbConnection that creates a connection if we're below the limit. Otherwise, it tries to provide a "spare" connection, failing with an exception if there are none.
public class DbConnection{
private static final int MAX_CONNS = 100;
private static int total...
Why does a function with no parameters (compared to the actual function definition) compile?
...at the function returns. This can not be an array type or a function type. If not given, then int
is assumed.
function-name is the name of the function.
parameter-list is the list of parameters that the function takes separated by commas. If no parameters are given, then the function
d...
How can I stop a Postgres script when it encounters an error?
Is there a way to specify that when executing a sql script it stops when encountering the first error on the script, it usually continues, regardless of previous errors.
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Use of “global” keyword in Python
...e documentation is that Python has a separate namespace for functions, and if I want to use a global variable in that function, I need to use global .
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Are the shift operators () arithmetic or logical in C?
In C, are the shift operators ( << , >> ) arithmetic or logical?
11 Answers
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