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Can dplyr package be used for conditional mutating?
... TRUE ~ NA_real_))
Added - arithmetic/na_if If the values are numeric and the conditions (except for the default value of NA at the end) are mutually exclusive, as is the case in the question, then we can use an arithmetic expression such that each term is multiplied by the desired result using...
API Versioning for Rails Routes
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The original form of this answer is wildly different, and can be found here. Just proof that there's more than one way to skin a cat.
I've updated the answer since to use namespaces and to use 301 redirects -- rather than the default of 302. Thanks to pixeltrix and Bo Jeanes fo...
How to reverse a singly linked list using only two pointers?
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Any alternative? No, this is as simple as it gets, and there's no fundamentally-different way of doing it. This algorithm is already O(n) time, and you can't get any faster than that, as you must modify every node.
It looks like your code is on the right track, but it's not...
How to identify all stored procedures referring a particular table
I created a table on development environment for testing purpose and there are few sp's which are refreing this table. Now I have have to drop this table as well as identify all sp's which are referring this table. I am facing difficulty to find list of all sp's. Please suggest some query by assumin...
MySQL Data - Best way to implement paging?
...ments, the first argument specifies the offset of the first row to return, and the second specifies the maximum number of rows to return. The offset of the initial row is 0 (not 1):
SELECT * FROM tbl LIMIT 5,10; # Retrieve rows 6-15
To retrieve all rows from a certain offset up to the end of the r...
Difference between Iterator and Listiterator?
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And the reason why you can't do that with a Set is simple: There is not "current point": Elements have no index and there is no usefull way you can add an element "before" or "after" another one.
– Joach...
PHP cURL vs file_get_contents
...ests where the header, HTTP request method, timeout, cookiejar, redirects, and other important things do not matter.
fopen() with a stream context or cURL with setopt are powerdrills with every bit and option you can think of.
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Is there a tool to convert JavaScript files to TypeScript [closed]
...cript, too. Nevertheless you can change the extension of a .js file to .ts and pass this file to the TypeScript compiler. This really confused me and I asked the question in the TypeScript IRC channel on freenode. It turned out that the Typescript compiler checks its input for valid JavaScript and j...
Difference between JSONObject and JSONArray
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When you are working with JSON data in Android, you would use JSONArray to parse JSON which starts with the array brackets. Arrays in JSON are used to organize a collection of related items (Which could be JSON objects).
For example: [{"name":"item 1"},{"name": "...
Pad a number with leading zeros in JavaScript [duplicate]
...ements. " - I don't think that's correct. It just sets the length property and join iterates length times. Access of an undefined property always returns undefined. See "5" in Array(5) vs "0" in [1]
– Benjamin Gruenbaum
Jul 24 '14 at 11:56
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