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Remove an entire column from a data.frame in R
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6 chr1 exon
As pointed out in the comments, here are some other possibilities:
Data[2] <- NULL # Wojciech Sobala
Data[[2]] <- NULL # same as above
Data <- Data[,-2] # Ian Fellows
Data <- Data[-2] # same as above
You can remove multiple columns via:
Data[1:2] <- list(N...
How to document class attributes in Python? [closed]
I'm writing a lightweight class whose attributes are intended to be publicly accessible, and only sometimes overridden in specific instantiations. There's no provision in the Python language for creating docstrings for class attributes, or any sort of attributes, for that matter. What is the expec...
JavaScript - cannot set property of undefined
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you never set d[a] to any value.
Because of this, d[a] evaluates to undefined, and you can't set properties on undefined.
If you add d[a] = {} right after d = {} things should work as expected.
Alternatively, you could use an object initializer:
d[a] = {
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Is Ruby pass by reference or by value?
@user object adds errors to the lang_errors variable in the update_lanugages method.
when I perform a save on the @user object I lose the errors that were initially stored in the lang_errors variable.
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Entity Framework - Invalid Column Name '*_ID"
I've narrowed this down to some issue between Code First and Database first EF, but I'm not sure how to fix it. I'll try to be as clear as I can, but I honestly am missing some of the understanding here myself. This is Entity Framework 4.4
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What does enctype='multipart/form-data' mean?
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When you make a POST request, you have to encode the data that forms the body of the request in some way.
HTML forms provide three methods of encoding.
application/x-www-form-urlencoded (the default)
multipart/form-data
text/plain
Work was being done on adding application/json, but that has...
How to get line count of a large file cheaply in Python?
...(hundreds of thousands of lines) in python. What is the most efficient way both memory- and time-wise?
40 Answers
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+ operator for array in PHP?
...e right-hand array appended to the left-hand array; for keys that exist in both arrays, the elements from the left-hand array will be used, and the matching elements from the right-hand array will be ignored.
So if you do
$array1 = ['one', 'two', 'foo' => 'bar'];
$array2 = ['three'...
Strings are objects in Java, so why don't we use 'new' to create them?
We normally create objects using the new keyword, like:
15 Answers
15
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How do you use “
I just finished reading about scoping in the R intro , and am very curious about the <<- assignment.
6 Answers
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