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Is there an R function for finding the index of an element in a vector?
In R, I have an element x and a vector v . I want to find the first index of an element in v that is equal to x . I know that one way to do this is: which(x == v)[[1]] , but that seems excessively inefficient. Is there a more direct way to do it?
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What does threadsafe mean?
...ently I tried to Access a textbox from a thread (other than the UI thread) and an exception was thrown. It said something about the "code not being thread safe" and so I ended up writing a delegate (sample from MSDN helped) and calling it instead.
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Generic Repository With EF 4.1 what is the point
As i dig deeper in to the DbContext, DbSet and associated interfaces, I am wondering why you would need to implement a separate "Generic" Repository around these implementations?
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RESTful Authentication
What does RESTful Authentication mean and how does it work? I can't find a good overview on Google. My only understanding is that you pass the session key (remeberal) in the URL, but this could be horribly wrong.
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Create a .txt file if doesn't exist, and if it does append a new line
I would like to create a .txt file and write to it, and if the file already exists I just want to append some more lines:
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Why should hash functions use a prime number modulus?
...g the "component parts" of the input (characters in the case of a string), and multiplying them by the powers of some constant, and adding them together in some integer type. So for example a typical (although not especially good) hash of a string might be:
(first char) + k * (second char) + k^2 * ...
Eclipse: Referencing log4j.dtd in log4j.xml
I've been using log4j for quite a while now and I usually use this at the top of the log4j.xml (probably just like many others and according to Google this is the way to do it):
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Checkbox for nullable boolean
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I got it to work with
@Html.EditorFor(model => model.Foo)
and then making a Boolean.cshtml in my EditorTemplates folder and sticking
@model bool?
@Html.CheckBox("", Model.GetValueOrDefault())
inside.
sh...
Determine the data types of a data frame's columns
I'm using R and have loaded data into a dataframe using read.csv() . How do I determine the data type of each column in the data frame?
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How can I scale an image in a CSS sprite
...an you please tell me if it is possible/how I can crop off a smaller image and then scale the cropped off region before I lay it out?
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