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Convert column classes in data.table
I have a problem using data.table: How do I convert column classes? Here is a simple example: With data.frame I don't have a problem converting it, with data.table I just don't know how:
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How do I read CSV data into a record array in NumPy?
I wonder if there is a direct way to import the contents of a CSV file into a record array, much in the way that R's read.table() , read.delim() , and read.csv() family imports data to R's data frame?
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How do I loop through a date range?
I'm not even sure how to do this without using some horrible for loop/counter type solution. Here's the problem:
16 Answer...
Can not connect to local PostgreSQL
I've managed to bork my local development environment.
21 Answers
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How do I represent a time only value in .NET?
Is there a way one can represent a time only value in .NET without the date? For example, indicating the opening time of a shop?
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Should CSS always preceed Javascript?
In countless places online I have seen the recommendation to include CSS prior to JavaScript. The reasoning is generally, of this form :
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Java HashMap performance optimization / alternative
I want to create a large HashMap but the put() performance is not good enough. Any ideas?
25 Answers
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EC2 instance has no public DNS
A guy I work with gave me the EC2 credentials to log onto his EC2 console. I was not the one who set it up. Some of the instances show a public dns name and others have a blank public DNS. I want to be able to connect to the instances that have a blank public DNS. I have not been able to figure out ...
Where can I find the TypeScript version installed in Visual Studio?
Maybe it's obvious, but I checked everywhere (besides the right place) and googled it. Nothing.
14 Answers
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`date` command on OS X doesn't have ISO 8601 `-I` option?
In a Bash script, I want to print the current datetime in ISO 8601 format (preferably UTC), and it seems that this should be as simple as date -I :
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