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Convert column classes in data.table
... You might want to add what names_factors is here. I guess it's taken from stackoverflow.com/a/20808945/1666063 so it's names_factors = c('fac1', 'fac2') in this case - which is column names.But it could also be column numbers for example 1;ncol(dt) which would convert all columns
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Is there a pretty print for PHP?
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)
Read more about print_r.
About the second parameter of print_r "true" from the documentation:
When this parameter is set to TRUE, print_r() will return the
information rather than print it.
share
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How to create correct JSONArray in Java using JSONObject
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I suppose you're getting this JSON from a server or a file, and you want to create a JSONArray object out of it.
String strJSON = ""; // your string goes here
JSONArray jArray = (JSONArray) new JSONTokener(strJSON).nextValue();
// once you get the array, you ...
How to make a smaller RatingBar?
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@Denny Content is available from Google Cache. I'm not updating the post with the content as I haven't looked at Android rating bars in years, and am not certain if the content in that link is still valid.
– Farray
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How to prevent Browser cache for php site
...ricer (a Linux distro known for "going fast" by being excessively compiled from source and architecture-tuned) I'd clock a stat call. Without filesystem cache, 16ns, tops? With cache, reliably < 8ns. Nanoseconds. And on my system MD5 can process 754 MiB/s without blinking. (openssl speed md5...
Should I use a data.frame or a matrix?
...haring @Gavin Simpson! Could you introduce a bit more about how to go back from 1-6 to a-f?
– YJZ
Jul 20 '15 at 14:40
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jQuery: how to change title of document during .ready()?
...Ruby on Rails, and in one of the layouts i have a need to read in a string from a div and set that as the title of the document. What is correct way (if any) to set the title of the document?
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OOP vs Functional Programming vs Procedural [closed]
...problems.
In a purely procedural style, data tends to be highly decoupled from the functions that operate on it.
In an object oriented style, data tends to carry with it a collection of functions.
In a functional style, data and functions tend toward having more in common with each other (as in L...
Why do I need Transaction in Hibernate for read-only operations?
... is DB specific. E.g. MySQL added support for this only in InnoDB starting from 5.6.4 version.
If you're not using JDBC directly, but rather an ORM, that might be problematic. For instance Hibernate community says that working outside of transaction might cause unpredictable behavior. This is becaus...
push_back vs emplace_back
...o, so I asked the same question on the Visual C++ blog. Here is the answer from Stephan T Lavavej, the official maintainer of the Visual C++ standard library implementation at Microsoft.
Q: Are beta 2 emplace functions just some kind of placeholder right now?
A: As you may know, variadic te...