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Aggregate / summarize multiple variables per group (e.g. sum, mean)
... The recast function (also from reshape2) integrates the melt and dcast function in one go for tasks like this: recast(df1, year + month ~ variable, sum, id.var = c("date", "year", "month"))
– Jaap
May 13 '16 at 6:17
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val-mutable versus var-immutable in Scala
...that means is that, if I have an expression "e", I could make a val x = e, and replace e with x. This is the property that mutability break. Whenever you need to make a design decision, maximize for referential transparency.
As a practical matter, a method-local var is the safest var that exists, s...
When to use nested classes and classes nested in modules?
I'm pretty familiar with when to use subclasses and modules, but more recently I've been seeing nested classes like this:
5...
Error: “The sandbox is not in sync with the Podfile.lock…” after installing RestKit with cocoapods
...ocoapods.
after resolving RestKit dependency for my project with cocoapods and trying to build it, I face this error:
40 A...
How to get year/month/day from a date object?
...ar();
newdate = year + "/" + month + "/" + day;
or you can set new date and give the above values
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Laravel Eloquent groupBy() AND also return count of each group
... table that contains, amongst other columns, a column of browser versions. And I simply want to know from the record-set, how many of each type of browser there are. So, I need to end up with something like this: Total Records: 10; Internet Explorer 8: 2; Chrome 25: 4; Firefox 20: 4. (All adding up ...
What's the difference between unit, functional, acceptance, and integration tests? [closed]
What is the difference between unit, functional, acceptance, and integration testing (and any other types of tests that I failed to mention)?
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Open and write data to text file using Bash?
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What if my text is something like this and for any reason, I can't use curl or wget?
– asedsami
Dec 28 '16 at 3:53
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Django: multiple models in one template using forms [closed]
I'm building a support ticket tracking app and have a few models I'd like to create from one page. Tickets belong to a Customer via a ForeignKey. Notes belong to Tickets via a ForeignKey as well. I'd like to have the option of selecting a Customer (that's a whole separate project) OR creating a new ...
Obtain form input fields using jQuery?
... In newer versions of jQuery, Simon_Weaver's answer is more robust and easier.
– MightyE
May 3 '10 at 21:27
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