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How to update Ruby to 1.9.x on Mac?
I have created a new user account on my mac and I am trying to update to the current version of ruby on it (1.9.2) from the snow leopard default of 1.8.7. Can somebody point me to tutorial or explain the best method to update Ruby on my mac from 1.8 to 1.9.2? Thanks
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Apache Spark: The number of cores vs. the number of executors
I'm trying to understand the relationship of the number of cores and the number of executors when running a Spark job on YARN.
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Use RSA private key to generate public key?
I don't really understand this one:
9 Answers
9
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round() for float in C++
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there is also lround and llround for integral results
– sp2danny
Feb 23 '15 at 11:55
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How do you match only valid roman numerals with a regular expression?
...L|L?X{0,3})(IX|IV|V?I{0,3})$
Breaking it down, M{0,4} specifies the thousands section and basically restrains it to between 0 and 4000. It's a relatively simple:
0: <empty> matched by M{0}
1000: M matched by M{1}
2000: MM matched by M{2}
3000: MMM matched by M{3}
4000:...
Xcode 6 beta 2 issue exporting .ipa: “Your account already has a valid iOS distribution certificate”
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This is what worked for me.
On my machine I kept both Xcode 5 and Xcode 6 beta.
From Xcode 6 beta, Archive the project. Close Xcode 6.
Open Xcode 5, go to Organizer and export as Ad Hoc build with proper provisioning profile.
That's it!
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Facebook database design?
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Keep a friend table that holds the UserID and then the UserID of the friend (we will call it FriendID). Both columns would be foreign keys back to the Users table.
Somewhat useful example:
Table Name: User
Columns:
UserID PK
EmailAddress
Password
Ge...
Best way to merge two maps and sum the values of same key?
I want to merge them, and sum the values of same keys. So the result will be:
15 Answers
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What's the fastest way to loop through an array in JavaScript?
...dern browsers:
https://jsben.ch/wY5fo
Currently, the fastest form of loop (and in my opinion the most syntactically obvious).
A standard for-loop with length caching
var i = 0, len = myArray.length;
while (i < len) {
// your code
i++
}
I would say, this is definitely ...
Getting the first and last day of a month, using a given DateTime object
I want to get the first day and last day of the month where a given date lies in. The date comes from a value in a UI field.
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