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Speed up the loop operation in R
...Biggest problem and root of ineffectiveness is indexing data.frame, I mean all this lines where you use temp[,].
Try to avoid this as much as possible. I took your function, change indexing and here version_A
dayloop2_A <- function(temp){
res <- numeric(nrow(temp))
for (i in 1:nrow(te...
How to check if a variable is set in Bash?
...
(Usually) The right way
if [ -z ${var+x} ]; then echo "var is unset"; else echo "var is set to '$var'"; fi
where ${var+x} is a parameter expansion which evaluates to nothing if var is unset, and substitutes the string x otherw...
Will iOS launch my app into the background if it was force-quit by the user?
... Unlike the application:didReceiveRemoteNotification: method, which is
called only when your app is running in the foreground, the system
calls this method when your app is running in the foreground or
background. In addition, if you enabled the remote notifications
background mode, the sys...
Is mathematics necessary for programming? [closed]
...m high school or fresh year college math, no more no less, and that almost all of programming tasks can be achieved without even need for advanced math. He argued, however, that algorithms are fundamental & must-have asset for programmers.
...
NPM clean modules
Is there a way to get npm to unbuild all the modules under node_modules? Something like npm rebuild that removes all build artifacts but doesn't rebuild them?
...
How to initialize a List to a given size (as opposed to capacity)?
...ount copies of the reference passed for the value parameter - so they will all refer to the same object. That may or may not be what you want, depending on your use case.
EDIT: As noted in comments, you could make Repeated use a loop to populate the list if you wanted to. That would be slightly fas...
Why use the INCLUDE clause when creating an index?
...e lowest/leaf level, rather than in the index tree.
This makes the index smaller because it's not part of the tree
INCLUDE columns are not key columns in the index, so they are not ordered.
This means it isn't really useful for predicates, sorting etc as I mentioned above. However, it may be useful...
Differences between git pull origin master & git pull origin/master
... checked-out branch.
git pull origin/master will pull changes from the locally stored branch origin/master and merge that to the local checked-out branch. The origin/master branch is essentially a "cached copy" of what was last pulled from origin, which is why it's called a remote branch in git par...
How to change column order in a table using sql query in sql server 2005?
...er when you make a "SELECT *". I'm a developer and do this kind of queries all the time. You can spare some time with a good pre-defined column order. From any other standpoint, of course, it has no sense: nothing should depend on the column order. By the way, there is an ORDINAL_POSITION column qhe...
When to use PNG or JPG in iPhone development?
...more compressed image formats, and thus be slower to display.
JPG's are smaller to store, but lossy (amount depends on compression level), and to display them requires a much more complicated decoding algorithm. But the typical compression and image quality is usually quite sufficient for photos.
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