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Set default CRAN mirror permanent in R

...?Startup: The path of this file is taken from the value of the R_PROFILE environment variable (after tilde expansion). If this variable is unset, the default is R_HOME/etc/Rprofile.site, which is used if it exists (which it does not in a 'factory-fresh' installation)...
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Secret copy to clipboard JavaScript function in Chrome and Firefox?

...learConsoleMessages(); } > copy function (object) { if (injectedScript._type(object) === "node") object = object.outerHTML; InjectedScriptHost.copyText(object); } While the Firebug source also defines a list of functions: this.clear = function() // no web page interaction { Firebug.Cons...
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How to find Unused Amazon EC2 Security groups

...AWS CLI tool, I found an easy way to get what I need: First, get a list of all security groups aws ec2 describe-security-groups --query 'SecurityGroups[*].GroupId' --output text | tr '\t' '\n' Then get all security groups tied to an instance, then piped to sort then uniq: aws ec2 describe-instance...
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Why use a public method in an internal class?

...presents the key, documented functionality provided by this object." Basically, my attitude is: suppose I decided to make this internal class into a public class. In order to do that, I want to change exactly one thing: the accessibility of the class. If turning an internal class into a public clas...
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validation custom message for rails 3

...ant to remove the field title from the message you should use this on your _form.htmk.erb view: As you can see inside this view: <ul> <% @article.errors.full_messages.each do |msg| %> <li><%= msg %></li> <% end %> </ul> Replace it by: <ul> ...
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MySQL check if a table exists without throwing an exception

...PDO syntax for it, but this seems pretty straight-forward: $result = mysql_query("SHOW TABLES LIKE 'myTable'"); $tableExists = mysql_num_rows($result) > 0; share | improve this answer ...
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How to create local notifications?

...thorizationOptionAlert) completionHandler:^(BOOL granted, NSError * _Nullable error) { if (!error) { NSLog(@"request authorization succeeded!"); [self showAlert]; } }]; -(void)showAlert { UIAlertController *objAlertControlle...
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How to parse JSON in Scala using standard Scala classes?

... { "languages": [{ "name": "English", "is_active": true, "completeness": 2.5 }, { "name": "Latin", "is_active": false, "completeness": 0.9 }] } """.stripMargin val result = for { Some(M(m...
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How do I get the picture size with PIL?

...#2: Pygame import pygame img = pygame.image.load(filepath) width = img.get_width() height = img.get_height() share | improve this answer | follow | ...
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How to log PostgreSQL queries?

How to enable logging of all SQL executed by PostgreSQL 8.3? 10 Answers 10 ...