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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...pread(tmp, y, z)
## x a b c
## 1 x 1 2 3
## 2 y 3 3 2
Using reshape2:
One of the first steps toward the tidyverse was the reshape2 package.
To get a matrix use acast:
library(reshape2)
acast(tmp, x~y, value.var="z")
## a b c
## x 1 2 3
## y 3 3 2
Or to get a data frame, use dcast, as here...
Is modern C++ becoming more prevalent? [closed]
...ou could learn about if you really wanted to. And there was certainly no one telling me that destructors could be harnessed to help manage memory.
Today, everywhere I look I see RAII and SFINAE and STL and Boost and, well, Modern C++. Even people who are just getting started with the language s...
Ruby class instance variable vs. class variable
... What is the difference between self.things and self.class.things you mentioned in code ?
– cyborg
Jun 26 '18 at 7:53
...
Get the first element of an array
...uld be passed by reference. Nice workaround btw
– Simone
Mar 21 '12 at 13:55
191
Isn't this a lit...
finding and replacing elements in a list
I have to search through a list and replace all occurrences of one element with another. So far my attempts in code are getting me nowhere, what is the best way to do this?
...
How to have the formatter wrap code with IntelliJ?
...
I would like to add one keyword here, which is what one may be looking for: this is what it is called a hard wrap (as opposed to soft wrap -- see the difference here).
– iled
Feb 5 '17 at 22:32
...
Celery Received unregistered task of type (run example)
...
celeryd is obsolete. Now one should run celery worker e.g for Django like this celery --app=your_app.celery worker --loglevel=info
– andilabs
Jan 14 '16 at 11:25
...
Why does calling a method in my derived class call the base class method?
... attach different keywords to your method.
1. Abstract classes
The first one is abstract. abstract methods simply point to nowhere:
If your class contains abstract members, it also needs to be marked as abstract, otherwise the compiler will not compile your application. You cannot create instan...
MySQL Cannot drop index needed in a foreign key constraint
...e
DROP KEY AID ;
gives error.
You can drop the index and create a new one in one ALTER TABLE statement:
ALTER TABLE mytable
DROP KEY AID ,
ADD UNIQUE KEY AID (AID, BID, CID, DID);
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imp...
Jquery live() vs delegate() [duplicate]
...enefits of using delegate to be so substantial as to be overwhelming.
The one benefit of live is that its syntax is very close to that of bind:
$('a.myClass').live('click', function() { ... });
delegate, however, uses a slightly more verbose syntax:
$('#containerElement').delegate('a.myClass', ...