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Pass a data.frame column name to a function
I'm trying to write a function to accept a data.frame ( x ) and a column from it. The function performs some calculations on x and later returns another data.frame. I'm stuck on the best-practices method to pass the column name to the function.
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Why I can't change directories using “cd”?
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Shell scripts are run inside a subshell, and each subshell has its own concept of what the current directory is. The cd succeeds, but as soon as the subshell exits, you're back in the interactive shell and nothing ever changed there.
One way to get around this is t...
Apache Spark: map vs mapPartitions?
What's the difference between an RDD's map and mapPartitions method? And does flatMap behave like map or like mapPartitions ? Thanks.
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PHP - Extracting a property from an array of objects
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this is the correct solution and will lead to the fact that every upcoming maintainer will be "wtf"'d :D
– Andreas Klinger
Jul 13 '09 at 11:56
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Why does “return list.sort()” return None, not the list?
... l = sorted(l.append('2')) (I just added semi-colon so you could cut/paste and run)
– JGFMK
May 30 '18 at 9:54
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Why fragments, and when to use fragments instead of activities?
In Android API 11+, Google has released a new class called Fragment .
11 Answers
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Nullable Foreign Key bad practice?
...hat bad practice or would you rather work with a link table between Orders and Customers? Although the relationship is 1 to n, a link table would make it n to n. On the other hand, with a link table, I don't have those NULLS anymore...
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What exactly does stringstream do?
I am trying to learn C++ since yesterday and I am using this document: http://www.cplusplus.com/files/tutorial.pdf (page 32) . I found a code in the document and I ran it. I tried inputting Rs 5.5 for price and an integer for quantity and the output was 0.
I tried inputting 5.5 and 6 and the output...
MySQL, better to insert NULL or empty string?
...a lot of different fields. Some of the fields are optional while some are mandatory. In my DB I have a table which holds all these values, is it better practice to insert a NULL value or an empty string into the DB columns where the user didn't put any data?
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Function in JavaScript that can be called only once
...y once, in each time after the first it won't be executed. I know from C++ and Java about static variables that can do the work but I would like to know if there is a more elegant way to do this?
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