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data.table vs dplyr: can one do something well the other can't or does poorly?
..., keyby = .(x,y)][DT2][, z := z*mul][]
# dplyr equivalent
DF1 %>% group_by(x, y) %>% summarise(z = sum(z)) %>%
right_join(DF2) %>% mutate(z = z * mul)
2) do it all in one go (using by = .EACHI feature):
DT1[DT2, list(z=sum(z) * mul), by = .EACHI]
What is the advantage?
We do...
How to make CSS width to fill parent?
...dited Jul 29 '15 at 18:10
jak89 _1
2588 bronze badges
answered Oct 1 '14 at 12:31
TigsarTigsar
...
PEP 8, why no spaces around '=' in keyword argument or a default parameter value?
...able assignment.
For example, there is plenty of code like this:
kw1 = some_value
kw2 = some_value
kw3 = some_value
some_func(
1,
2,
kw1=kw1,
kw2=kw2,
kw3=kw3)
As you see, it makes complete sense to assign a variable to a keyword argument named exactly the same, so it improves r...
SVN:externals equivalent in Git?
...ateParsons but is it possible to omit revisions with git submodules... >_>
– Trejkaz
Sep 28 '16 at 3:22
...
How to pass the values from one activity to previous activity
... Intent(this,TextEntryActivity.class);
startActivityForResult(i, STATIC_INTEGER_VALUE);
Within the subactivity, rather than just closing the Activity when a user clicks the button, you need to create a new Intent and include the entered text value in its extras bundle. To pass it back to the p...
The provider is not compatible with the version of Oracle client
...t code comparison of managed vs unmanaged: http://docs.oracle.com/cd/E51173_01/win.122/e17732/intro005.htm#ODPNT148
Ensure you have downloaded the ODP.NET, Managed Driver Xcopy version only
From the downloaded zip file, copy and paste into your project directory:
Oracle.ManagedDataAccessDTC.dll
Or...
How to deal with persistent storage (e.g. databases) in Docker
...te --name hello
docker run -d -v hello:/container/path/for/volume container_image my_command
This means that the data-only container pattern must be abandoned in favour of the new volumes.
Actually the volume API is only a better way to achieve what was the data-container pattern.
If you create ...
return statement vs exit() in main()
...ay be even a core. If you need to exit w/o calling static destructors, use _exit .
– user3458
Jan 20 '09 at 14:46
7
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How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
... @MaxGontar, your mysql solution rocks, thx. what if in your @_TestTable you remove row#1>: SELECT 1, 10, '2009-03-04', 'john', 399 , this is, what if you have a single row for a given home value? thx.
– egidiocs
Nov 11 '11 at 3:44
...
Rails: FATAL - Peer authentication failed for user (PG::Error)
...velopment:
adapter: postgresql
encoding: unicode
database: kickrstack_development
host: localhost
pool: 5
username: kickrstack
password: secret
Make sure your user credentials are set correctly by creating a database and assigning ownership to your app's user to establish the connect...