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Trimming a huge (3.5 GB) csv file to read into R
...
My try with readLines. This piece of a code creates csv with selected years.
file_in <- file("in.csv","r")
file_out <- file("out.csv","a")
x <- readLines(file_in, n=1)
writeLines(x, file_out) # copy headers
B <- 300000 # depends how large is one pack
while(length(x)) {
...
What is the purpose of “android.intent.category.DEFAULT”?
...ies, then Android will present all candidates to the user and the user can select his preferred default.
Reference:
http://developer.android.com/guide/components/intents-filters.html
Extract from that page:
Android treats all implicit intents passed tostartActivity() as if they contained at ...
Determine font color based on background color
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I encountered similar problem. I had to find a good method of selecting contrastive font color to display text labels on colorscales/heatmaps. It had to be universal method and generated color had to be "good looking", which means that simple generating complementary color was not good ...
ALTER DATABASE failed because a lock could not be placed on database
... for a couple of minutes)
CREATE DATABASE TESTING123
GO
USE TESTING123;
SELECT NEWID() AS X INTO FOO
FROM sys.objects s1,sys.objects s2,sys.objects s3,sys.objects s4 ,sys.objects s5 ,sys.objects s6
Connections 2 and 3
set lock_timeout 5;
ALTER DATABASE TESTING123 SET SINGLE_USER WITH ROLLBACK...
Visual Studio debugging/loading very slow
...Options -> Debugging -> Symbols
Click on the "..." button and create/select a new folder somewhere on your local computer to store cached symbols. I named mine "Symbol caching" and put it in Documents -> Visual Studio 2012.
Click on "Load all symbols" and wait for the symbols to be download...
deciding among subprocess, multiprocessing, and thread in Python?
....
To understand how this is possible one should read about the features of select() (which can be built around the select() or poll() or similar OS system calls).
Basically it's all driven by the ability to make a request of the OS to sleep pending any activity on a list of file descriptors or some ...
How to make ruler always be shown in Sublime text 2?
...
As others have stated before me, select Preferences -> Settings-User and change
"rulers": [],
to
"rulers": [80],
in order to display one ruler at column 80.
Now for the rub, it seems that one must use a monospaced font in order to display rulers so y...
How to fix error “Updating Maven Project”. Unsupported IClasspathEntry kind=4?
...
Right-click on your project, select Maven -> Remove Maven Nature.
Open you terminal, go to your project folder and do mvn eclipse:clean
Right click on your Project and select “Configure -> Convert into Maven Project”
Now you got “Unsupporte...
Inserting a Python datetime.datetime object into MySQL
...
when iserting into t-sql
this fails:
select CONVERT(datetime,'2019-09-13 09:04:35.823312',21)
this works:
select CONVERT(datetime,'2019-09-13 09:04:35.823',21)
easy way:
regexp = re.compile(r'\.(\d{6})')
def to_splunk_iso(dt):
"""Converts the datetime ...
Java: notify() vs. notifyAll() all over again
...and the difference between these methods right), only one thread is always selected for further monitor acquisition.
That is not correct. o.notifyAll() wakes all of the threads that are blocked in o.wait() calls. The threads are only allowed to return from o.wait() one-by-one, but they each will...