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Counting the number of elements with the values of x in a vector
... x creates a logical vector which is TRUE at every location that x occurs, and when suming, the logical vector is coerced to numeric which converts TRUE to 1 and FALSE to 0.
However, note that for floating point numbers it's better to use something like: sum(abs(numbers - x) < 1e-6).
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When is an interface with a default method initialized?
....4.1 ought to cover this definitively. However, the behavior of Oracle JDK and OpenJDK (javac and HotSpot) differs from what's specified here. In particular, the Example 12.4.1-3 from this section covers interface initialization. The example as follows:
interface I {
int i = 1, ii = Test.out("i...
What is the difference between a var and val definition in Scala?
What is the difference between a var and val definition in Scala and why does the language need both? Why would you choose a val over a var and vice versa?
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write a shell script to ssh to a remote machine and execute commands
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There are multiple remote linux machines, and I need to write a shell script which will execute the same set of commands in each machine. (Including some sudo operations). How can this be done using shell scripting?
You can do this with ssh, for example:
#!/bin/ba...
Difference between git checkout --track origin/branch and git checkout -b branch origin/branch
Does anybody know the difference between these two commands to switch and track a remote branch?
4 Answers
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Hidden features of Ruby
...actually wrote an gem at one point to do this, but my code was (a) a mess, and (b) slow. I'm very glad that the functionality has made it into core.
– James A. Rosen
Dec 14 '09 at 13:47
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What ports does RabbitMQ use?
...olution of node names in a cluster. Nodes must be able to reach each other and the port mapper daemon for clustering to work.
PORT 35197
set by inet_dist_listen_min/max Firewalls must permit traffic in this range to pass between clustered nodes
RabbitMQ Management console:
PORT 15672 for RabbitM...
Mongodb Explain for Aggregation framework
...t, $geonear at the beginning of a pipeline) as well as subsequent $lookup and $graphLookup stages. Once data has been fetched into the aggregation pipeline for processing (e.g. passing through stages like $project, $unwind, and $group) further manipulation will be in-memory (possibly using temporar...
Getting key with maximum value in dictionary?
...b':3000, 'c': 100}
max(stats.iteritems(), key=operator.itemgetter(1))[0]
And instead of building a new list in memory use stats.iteritems(). The key parameter to the max() function is a function that computes a key that is used to determine how to rank items.
Please note that if you were to have ...
Seeking clarification on apparent contradictions regarding weakly typed languages
I think I understand strong typing , but every time I look for examples for what is weak typing I end up finding examples of programming languages that simply coerce/convert types automatically.
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