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Painless way to install a new version of R?
Andrew Gelman recently lamented the lack of an easy upgrade process for R (probably more relevant on Windows than Linux). Does anyone have a good trick for doing the upgrade, from installing the software to copying all the settings/packages over?
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How to check if a file exists in Documents folder?
... if it was a main application you'll have access to the entire file system and you'll use the shared Documents directory. If you install it via iTunes or XCode you'll be using your applications' personal directory. It's nice to store files in your local directory for backup purposes.
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Bash/sh - difference between && and ;
I normally use ; to combine more than one command in a line, but some people prefer && . Is there any difference? For example, cd ~; cd - and cd ~ && cd - seems to make the same thing. What version is more portable, e.g. will be supported by a bash-subset like Android's shell ...
Create Directory When Writing To File In Node.js
I've been tinkering with Node.js and found a little problem. I've got a script which resides in a directory called data . I want the script to write some data to a file in a subdirectory within the data subdirectory. However I am getting the following error:
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CORS: Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true
...these questions :
Access-Control-Allow-Origin wildcard subdomains, ports and protocols
Cross Origin Resource Sharing with Credentials
Besides * is too permissive and would defeat use of credentials. So set http://localhost:3000 or http://localhost:8000 as the allow origin header.
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What is the correct value for the disabled attribute?
...the valid markup.
For HTML5, <input type="text" disabled /> is valid and used by W3C on their samples.
In fact, both ways works on all major browsers.
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What is the difference between t.belongs_to and t.references in rails?
What is the difference between t.references and t.belongs_to ?
Why are we having those two different words? It seems to me they do the same thing?
Tried some Google search, but find no explanation.
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A better similarity ranking algorithm for variable length strings
....com/articles/StrikeAMatch.html
Simon has a Java version of the algorithm and below I wrote a PL/Ruby version of it (taken from the plain ruby version done in the related forum entry comment by Mark Wong-VanHaren) so that I can use it in my PostgreSQL queries:
CREATE FUNCTION string_similarity(str...
django admin - add custom form fields that are not part of the model
... that based on these fields values I will build the long string expression and save it in the relevant model field.
5 Answe...
What is the Ruby (spaceship) operator?
...en return -1
if a = b then return 0
if a > b then return 1
if a and b are not comparable then return nil
It's useful for sorting an array.
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