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How to append rows to an R data frame
...rs of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame.
Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, defined as:
# pre-allocate space
f3 <- function(n){
df <- data.frame(x = numeric(n)...
Detach (move) subdirectory into separate Git repository
... Now I have found that one of the subdirectories is unrelated to the other and should be detached to a separate repository.
...
Android ImageView Zoom-in and Zoom-Out
I want to Zoom-in and Zoom-out an Android ImageView. I tried most of the samples but in all of them the image in the ImageView itself is getting Zoomed-in and Zoomed-out, while I want to Zoom-in and Zoom-out the ImageView. I want to increase the ImageView width and height while Zooming-in and reduce...
Is module __file__ attribute absolute or relative?
I'm having trouble understanding __file__ . From what I understand, __file__ returns the absolute path from which the module was loaded.
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Algorithm for classifying words for hangman difficulty levels as “Easy”,“Medium”, or “Hard”
...angman strategy
There's an idea that's implicit in some the other answers and comments, that the optimal strategy for the solver would be to base their decisions on the frequency of letters in English, or on the frequency of words in some corpus. This is a seductive idea, but it's not quite right. ...
__attribute__ - C/C++ - 清泛网 - 专注C/C++及内核技术
...e__可以设置函数属性（Function Attribute）、变量属性（Variabl GNU C的一大特色（却不被初学者所知）就是__attribute__机制。__attribute__可以设置函数属性（Function Attribute）、变量属性（Variable Attribute）和类型属性（Type Attribute）。
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When should we use mutex and when should we use semaphore
When should we use mutex and when should we use semaphore ?
12 Answers
12
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What are the use cases for selecting CHAR over VARCHAR in SQL?
...R(10) = 10 bytes (4 bytes of waste)
The bottom line is CHAR can be faster and more space-efficient for data of relatively the same length (within two characters length difference).
Note: Microsoft SQL has 2 bytes of overhead for a VARCHAR. This may vary from DB to DB, but generally, there is at lea...
Behaviour for significant change location API when terminated/suspended?
...stion, I have done a fair bit of testing (mostly on the train between home and work) and have confirmed that the behaviour for suspended apps is as I suspected at the end of the question.
That is, your suspended app is woken up, you don't receive any callbacks on your app delegate, instead you re...
What is more efficient? Using pow to square or just multiply it with itself?
What of these two methods is in C more efficient? And how about:
7 Answers
7
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