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How to append rows to an R data frame
....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), y = character(n), stringsAsFactors = FALSE)
for(i in 1:n){
df$x[i] <- i
df$y[i] <- toString(i)
...
Wait until all jQuery Ajax requests are done?
...quest might finish before the second even starts
semaphore++;
$.get('ajax/test1.html', function(data) {
semaphore--;
if (all_queued && semaphore === 0) {
// process your custom stuff here
}
});
semaphore++;
$.get('ajax/test2.html', function(data) {
semaphore--;
...
Swift: Testing optionals for nil
...I have this weird situation where I cannot figure out how to appropriately test for optionals.
14 Answers
...
Why is `std::move` named `std::move`?
...).
So what does move do in terms of generated object code?
Consider this test:
void
test(int& i, int& j)
{
i = j;
}
Compiled with clang++ -std=c++14 test.cpp -O3 -S, this produces this object code:
__Z4testRiS_: ## @_Z4testRiS_
.cfi_startproc
## BB#0:...
html5 localStorage error with Safari: “QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to
...to removeItem are ignored.
I believe the simplest fix (although I haven't tested this cross browser yet) would be to alter the function isLocalStorageNameSupported() to test that you can also set some value.
https://github.com/marcuswestin/store.js/issues/42
function isLocalStorageNameSupported()...
Copy constructor for a class with unique_ptr
...nique_ptr is not copyable, it is only moveable.
This will directly affect Test, which is, in your second, example also only moveable and not copyable.
In fact, it is good that you use unique_ptr which protects you from a big mistake.
For example, the main issue with your first code is that the po...
Why is isNaN(null) == false in JS?
...nvert the passed parameter to a number1 (equivalent to Number(x)) and then tests if the value is NaN. If the parameter can't be converted to a number, Number(x) will return NaN2. Therefore, if the conversion of parameter x to a number results in NaN, it returns true; otherwise, it returns false.
S...
Format a number as 2.5K if a thousand or more, otherwise 900
...i[i].value).toFixed(digits).replace(rx, "$1") + si[i].symbol;
}
/*
* Tests
*/
var tests = [
{ num: 1234, digits: 1 },
{ num: 100000000, digits: 1 },
{ num: 299792458, digits: 1 },
{ num: 759878, digits: 1 },
{ num: 759878, digits: 0 },
{ num: 123, digits: 1 },
{ num: 12...
Makefile variable as prerequisite
... variant
In my makefiles, I normally use an expression like:
deploy:
test -n "$(ENV)" # $$ENV
rsync . $(ENV).example.com:/var/www/myapp/
The reasons:
it's a simple one-liner
it's compact
it's located close to the commands which use the variable
Don't forget the comment which is impo...
Capitalize only first character of string and leave others alone? (Rails)
...
This should do it:
title = "test test"
title[0] = title[0].capitalize
puts title # "Test test"
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