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Pass a data.frame column name to a function
...l_name,col1,col2){
df$col_name <- df$col1 + df$col2
df
}
#Call foo() like this:
foo(dat,z,x,y)
The problem here is that df$col1 doesn't evaluate the expression col1. It simply looks for a column in df literally called col1. This behavior is described in ?Extract under the secti...
How to flatten nested objects with linq expression
...used: http://odetocode.com/blogs/scott/archive/2008/03/25/inner-outer-lets-all-join-together-with-linq.aspx
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Reset keys of array elements in php?
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To reset the keys of all arrays in an array:
$arr = array_map('array_values', $arr);
In case you just want to reset first-level array keys, use array_values() without array_map.
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What does Maven Update Project do in Eclipse?
...or doing a project update might revert what you have changed. There are usually some things I have to correct myself anyway though, such as build path exclusions that m2eclipse likes to put in and strange deployment assembly configurations.
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JPQL IN clause: Java-Arrays (or Lists, Sets…)?
I would like to load all objects that have a textual tag set to any of a small but arbitrary number of values from our database. The logical way to go about this in SQL would be to build an "IN" clause. JPQL allows for IN, but it seems to require me to specify every single parameter to IN directly (...
Can you add new statements to Python's syntax?
... a hands-on approach here: I'm going to add an until statement to Python.
All the coding for this article was done against the cutting-edge Py3k branch in the Python Mercurial repository mirror.
The until statement
Some languages, like Ruby, have an until statement, which is the complement to whi...
Check if a string contains another string
... @RoobieNuby That's just my default error handling. I put it in on all my functions because if something goes wrong, I want the staff to call me, not to try and fix it themselves.
– Sinister Beard
Dec 3 '14 at 9:16
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How to convert `git:` urls to `http:` urls
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helps when firewall blocks git protocol! :)
– Wojtek Turowicz
Jun 14 '13 at 15:36
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What is the difference between exit and return? [duplicate]
...hat is difference between return and exit statement in C programming when called from anywhere in a C program?
4 Answers
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Are list-comprehensions and functional functions faster than “for loops”?
...ike map() , filter() and reduce() faster than a for loop? Why, technically, they run in a C speed , while the for loop runs in the python virtual machine speed ?.
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