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data.table vs dplyr: can one do something well the other can't or does poorly?
I'm relatively familiar with data.table , 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 do I position one image on top of another in HTML?
I'm a beginner at rails programming, attempting to show many images on a page. Some images are to lay on top of others. To make it simple, say I want a blue square, with a red square in the upper right corner of the blue square (but not tight in the corner). I am trying to avoid compositing (with...
Problems with Android Fragment back stack
I've got a massive problem with the way the android fragment backstack seems to work and would be most grateful for any help that is offered.
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Iterate over object attributes in python
I have a python object with several attributes and methods. I want to iterate over object attributes.
8 Answers
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Bash if [ false ] ; returns true
Been learning bash this week and ran into a snag.
6 Answers
6
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PHP's array_map including keys
...ond_key" => "second_value");
array_walk($test_array, function(&$a, $b) { $a = "$b loves $a"; });
var_dump($test_array);
// array(2) {
// ["first_key"]=>
// string(27) "first_key loves first_value"
// ["second_key"]=>
// string(29) "second_key loves second_value"
// }
It does ...
How do I use $rootScope in Angular to store variables?
How do I use $rootScope to store variables in a controller I want to later access in another controller? For example:
8 A...
Replacing NAs with latest non-NA value
In a data.frame (or data.table), I would like to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
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How to select all records from one table that do not exist in another table?
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SELECT t1.name
FROM table1 t1
LEFT JOIN table2 t2 ON t2.name = t1.name
WHERE t2.name IS NULL
Q: What is happening here?
A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 with the same value for ...
Why is the minimalist, example Haskell quicksort not a “true” quicksort?
Haskell's website introduces a very attractive 5-line quicksort function , as seen below.
11 Answers
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