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Fastest way to replace NAs in a large data.table
....805 12.301 134.985
system.time(a_andrie = f_andrie(dt1))
Error: cannot allocate vector of size 305.2 Mb
Timing stopped at: 14.541 7.764 68.285
system.time(f_dowle(dt1))
user system elapsed
7.452 4.144 19.590 # EDIT has faster than this
identical(a_gdata, dt1)
[1] TRUE
Note th...
Git pull after forced update
... the working tree since <commit> are discarded.
If you want to actually keep whatever changes you've got locally - do a --soft reset instead. Which will update the commit history for the branch, but not change any files in the working directory (and you can then commit them).
Rebase
You ca...
How to fix corrupted git repository?
... have a corrupted local repo, but a trusted remote.
# This script replaces all your history with that of the remote.
# If there is a .git, it is backed up as .git_old, removing the last backup.
# This does not affect your working tree.
#
# This does not currently work with submodules!
# This will ab...
Convert datetime to Unix timestamp and convert it back in python
...m UTC.
If you have, or can upgrade to, Python 3.3 or later, you can avoid all of these problems by just using the timestamp method instead of trying to figure out how to do it yourself. And even if you don't, you may want to consider borrowing its source code.
(And if you can wait for Python 3.4, ...
Is there a difference between foreach and map?
...important point to mention (this is particularly true in Scala) is that a call to map does not result in the execution of its underlying logic until when the expected transformed list is summoned. In contrast, foreach's operation is computed immediately.
– solimant
...
How to write a simple database engine [closed]
...ny, so I am hoping someone else can point me in the right direction. Basically, I would like information on the following:
...
Fragment or Support Fragment?
...
From my experience, using the same fragment implementation on all Android devices is a great advantage. I could not get rid of all NullPointerExceptions when state is saved on Android 4.0 using native fragments, with the support library they are all gone. Also I could not see any disadv...
Where am I? - Get country
An android mobile actually does know quite well where it is - but is there a way of retrieving the country by something like a country code?
...
Suppress command line output
... invocation to this:
taskkill /im "test.exe" /f >nul 2>&1
and all will be better.
That works because stdout is file descriptor 1, and stderr is file descriptor 2 by convention. (0 is stdin, incidentally.) The 2>&1 copies output file descriptor 2 from the new value of 1, which wa...
Custom method names in ASP.NET Web API
...I want to have a method named Authenticate. I see examples of how to do GetAll, GetOne, Post, and Delete, however what if I want to add extra methods into these services? For instance, my UsersService should have a method called Authenticate where they pass in a username and password, however it doe...