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Simple way to create matrix of random numbers
...
You can drop the range(len()):
weights_h = [[random.random() for e in inputs[0]] for e in range(hiden_neurons)]
But really, you should probably use numpy.
In [9]: numpy.random.random((3, 3))
Out[9]:
array([[ 0.37052381, 0.03463207, 0.10669077],
[ 0.05...
Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?
...cle Database 11g Release 2 and above - by default, no, but an alternative called edition-based redefinition exists
Older versions of Oracle - no; DDL causes an implicit commit
SQL Server - yes
Sybase Adaptive Server - yes
DB2 - yes
Informix - yes
Firebird (Interbase) - yes
SQLite also appears to h...
Ruby on Rails: How can I revert a migration with rake db:migrate?
...to revert.
eg. if you want to revert a migration with file name 3846656238_create_users.rb
rake db:migrate:down VERSION=3846656238
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In Swift how to call method with parameters on GCD main thread?
...() + 0.1) {
// your code here
}
Older versions of Swift used:
dispatch_async(dispatch_get_main_queue(), {
let delegateObj = UIApplication.sharedApplication().delegate as YourAppDelegateClass
delegateObj.addUIImage("yourstring")
})
...
Best way to pretty print a hash
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require 'pp'
pp my_hash
Use pp if you need a built-in solution and just want reasonable line breaks.
Use awesome_print if you can install a gem. (Depending on your users, you may wish to use the index:false option to turn off displaying arr...
How does having a dynamic variable affect performance?
...Generator();
if (!method.IsStatic)
{
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Unbox_Any, method.DeclaringType);
}
var parameters = method.GetParameters();
for (int i = 0; i < parameters.Length; i++)
{
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCo...
How do I append text to a file?
...ther source.
Or else entered at the keyboard, doesn't matter.
^D
Essentially, you can dump any text you want into the file. CTRL-D sends an end-of-file signal, which terminates input and returns you to the shell.
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How can I use a search engine to search for special characters? [closed]
...ace before it, in which case it is a negative sign.)
The underscore symbol _ is not ignored when it connects two words, e.g. [ quick_sort ].
As such, it is not well suited for these types of searchs. Google Code however does have syntax for searching through their code projects, that includes a ro...
How to dismiss keyboard iOS programmatically when pressing return
...s delegate to current viewcontroller and then:
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
Objective-C:
[self.view endEditing:YES];
or
Set text field's delegate to current viewcontroller and then:
- (BOOL)textFie...
Citing the author of a blockquote using Markdown syntax
...ld like to have the quote followed by a citation beneath it, but right now all it does is blockquote the whole line. How does one do this in markdown syntax?
...