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Count number of objects in list [closed]
...'s put some stuff in it - 3 components/indexes/tags (whatever you want to call it) each with differing amounts of elements:
> mylist <- list(record1=c(1:10),record2=c(1:5),record3=c(1:2))
If you are interested in just the number of components in a list use:
> length(mylist)
[1] 3
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How to split a comma-separated value to columns
...IT() (which does not carry the fragment's position, a huge fail!) or the really fast JSON-hack. For older version look for the well-known XML-hack (json and xml details here). Or look for one of the may iTVFs based on recursive CTEs.
– Shnugo
Nov 21 '19 at 10:3...
Best way to extract a subvector from a vector?
Suppose I have a std::vector (let's call it myVec ) of size N . What's the simplest way to construct a new vector consisting of a copy of elements X through Y, where 0
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Why does Java's hashCode() in String use 31 as a multiplier?
... i == (i << 5) - i. Modern VMs do this sort of optimization automatically.
(from Chapter 3, Item 9: Always override hashcode when you override equals, page 48)
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Build error: You must add a reference to System.Runtime
...targeting 4.52, no known PCL but many nuGet packages. I believe that uninstalling VS2013 triggered this but I do not know that as fact. Error only surfaced in Views that referenced X-PagedList. Adding reference to project web.config (not views web.config) fixed it.
– Greg Ter...
SSL Error When installing rubygems, Unable to pull data from 'https://rubygems.org/
I am trying to do the Michael Hartl tutorial. When I attempt to install rails 3.2.14 in my gemset, I get the following issue:
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Converting string into datetime
...time is the main routine for parsing strings into datetimes. It can handle all sorts of formats, with the format determined by a format string you give it:
from datetime import datetime
datetime_object = datetime.strptime('Jun 1 2005 1:33PM', '%b %d %Y %I:%M%p')
The resulting datetime object is...
Font from origin has been blocked from loading by Cross-Origin Resource Sharing policy
I'm receiving the following error on a couple of Chrome browsers but not all. Not sure entirely what the issue is at this point.
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What is the method for converting radians to degrees?
I run into this occasionally and always forget how to do it.
12 Answers
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Does Python SciPy need BLAS?
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The SciPy webpage used to provide build and installation instructions, but the instructions there now rely on OS binary distributions. To build SciPy (and NumPy) on operating systems without precompiled packages of the required libraries, you must build and then statically...