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Quickly reading very large tables as dataframes

I have very large tables (30 million rows) that I would like to load as a dataframes in R. read.table() has a lot of convenient features, but it seems like there is a lot of logic in the implementation that would slow things down. In my case, I am assuming I know the types of the columns ahead o...
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How do I reverse an int array in Java?

I am trying to reverse an int array in Java. 43 Answers 43 ...
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How do I get time of a Python program's execution?

I have a command line program in Python that takes a while to finish. I want to know the exact time it takes to finish running. ...
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Why do people use Heroku when AWS is present? What distinguishes Heroku from AWS? [closed]

I'm a beginner RoR programmer who's planning to deploy my app using Heroku. Word from my other advisor friends says that Heroku is really easy, good to use. The only problem is that I still have no idea what Heroku does... ...
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Selecting empty text input using jQuery

How do I identify empty textboxes using jQuery? I would like to do it using selectors if it is at all possible. Also, I must select on id since in the real code where I want to use this I don't want to select all text inputs. ...
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Why isn't `int pow(int base, int exponent)` in the standard C++ libraries?

I feel like I must just be unable to find it. Is there any reason that the C++ pow function does not implement the "power" function for anything except float s and double s? ...
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What’s the best RESTful method to return total number of items in an object?

I’m developing a REST API service for a large social networking website I’m involved in. So far, it’s working great. I can issue GET , POST , PUT and DELETE requests to object URLs and affect my data. However, this data is paged (limited to 30 results at a time). ...
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npm global path prefix

I am being more cautious than usual because I have been confused by the behavior of npm in the past. 10 Answers ...
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In C#, how do I calculate someone's age based on a DateTime type birthday?

A given DateTime Type represents a person's birthday. How could I calculate his / her age in years? 61 Answers ...
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Format date in a specific timezone

I'm using Moment.js to parse and format dates in my web app. As part of a JSON object, my backend server sends dates as a number of milliseconds from the UTC epoch (Unix offset). ...