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How to Correctly Use Lists in R?
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Just to address the last part of your question, since that really points out the difference between a list and vector in R:
Why do these two expressions not return the same result?
x = list(1, 2, 3, 4); x2 = list(1:4)
A list can contain any other class as each element. So you can ha...
Check if database exists in PostgreSQL using shell
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(4 rows)
Using the naive approach means that searching for a database called "List, "Access" or "rows" will succeed. So we pipe this output through a bunch of built-in command line tools to only search in the first column.
The -t flag removes headers and footers:
my_db | my_user | UTF...
Replace a value in a data frame based on a conditional (`if`) statement
In the R data frame coded for below, I would like to replace all of the times that B
appears with b .
8 Answers
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Undo a git stash
...ll not reset what is in the staging directory, so you will have to restage all that (which can be annoying if you had just done a complex git add -p
– Nick
Jan 2 '13 at 17:31
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Pros and cons of Java rules engines [closed]
... good. Could you please tell me where to use drool and where to Jess? Basically , I'm expecting the answer more related diff. b/w drool and Jess.
– Tony
Jul 1 '10 at 17:58
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How to create .pfx file from certificate and private key?
I need .pfx file to install https on website on IIS.
15 Answers
15
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Does Django scale? [closed]
...erformance. That would be 432,000 hits per hour. Response times aren't small (our transactions are large) but there's no degradation from our baseline performance as the load increases.
We're using Apache front-ending Django and MySQL. The OS is Red Hat Enterprise Linux (RHEL). 64-bit. We use ...
How to implement a binary tree?
...ice implementation. I'm just here to point out some style stuff. python usually does node is not None instead of your (node!=None). Also, you can use the __str__ function instead of the printTree method.
– Jeff Mandell
Oct 18 '15 at 2:30
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Is using 'var' to declare variables optional? [duplicate]
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@codemeit : javascript is full of pitfalls like this, but all in all it's a beautiful and very pleasant language. Don't hate it. Just know the pitfalls and leave them out of your code.
– Stefano Borini
Mar 21 '10 at 1:25
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Immutability of Strings in Java
...t, and changing a reference. s2 still points to the same object as we initially set s1 to point to. Setting s1 to "Help!" only changes the reference, while the String object it originally referred to remains unchanged.
If strings were mutable, we could do something like this:
String s1 = "Hello";
St...