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data.table vs dplyr: can one do something well the other can't or does poorly?
...able , not so much with dplyr . I've read through some dplyr vignettes and examples that have popped up on SO, and so far my conclusions are that:
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How can I apply a function to every row/column of a matrix in MATLAB?
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Many built-in operations like sum and prod are already able to operate across rows or columns, so you may be able to refactor the function you are applying to take advantage of this.
If that's not a viable option, one way to do it is to collect the rows or c...
Search for one value in any column of any table inside a database
...s Kondreddi
-- Site: http://vyaskn.tripod.com
-- Tested on: SQL Server 7.0 and SQL Server 2000
-- Date modified: 28th July 2002 22:50 GMT
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @Sear...
Most efficient method to groupby on an array of objects
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Here is one that outputs array and not object: groupByArray(xs, key) { return xs.reduce(function (rv, x) { let v = key instanceof Function ? key(x) : x[key]; let el = rv.find((r) => r && r.key === v); ...
How do I create and read a value from cookie?
How can I create and read a value from a cookie in JavaScript?
19 Answers
19
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How to change column datatype in SQL database without losing data
I have SQL Server database and I just realized that I can change the type of one of the columns from int to bool .
11 A...
Catching error codes in a shell pipe
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If you really don't want the second command to proceed until the first is known to be successful, then you probably need to use temporary files. The simple version of that is:
tmp=${TMPDIR:-/tmp}/mine.$$
if ./a > $tmp.1
then
if ./b <$tmp.1 >$tmp.2
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How to Create Multiple Where Clause Query Using Laravel Eloquent?
I'm using the Laravel Eloquent query builder and I have a query where I want a WHERE clause on multiple conditions. It works, but it's not elegant.
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OAuth 2.0: Benefits and use cases — why?
Could anyone explain what's good about OAuth2 and why we should implement it? I ask because I'm a bit confused about it — here's my current thoughts:
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LINQ Aggregate algorithm explained
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The easiest-to-understand definition of Aggregate is that it performs an operation on each element of the list taking into account the operations that have gone before. That is to say it performs the action on the first and second element and carr...