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Why doesn't C have unsigned floats?
...e? -8. But what would that mean in a system without negative numbers. FLOAT_MAX - 8 perhaps? Actually, that doesn't work as FLOAT_MAX - 8 is FLOAT_MAX due to precision effects so things are even more screwy. What if it was part of a more complex expression:
float a = 2.0f, b = 10.0f, c = 20.0f, d =...
How to sort an array in descending order in Ruby
... { ary.sort{ |a,b| a[:bar] <=> b[:bar] }.reverse } }
x.report("sort_by -a[:bar]") { n.times { ary.sort_by{ |a| -a[:bar] } } }
x.report("sort_by a[:bar]*-1") { n.times { ary.sort_by{ |a| a[:bar]*-1 } } }
x.report("sort_by.reverse!") { n.times { ary.sort_by{ |a| a[:bar] }.reverse } }
e...
Is Safari on iOS 6 caching $.ajax results?
..."no-cache" just to POSTs if you wish like this in Apache:
SetEnvIf Request_Method "POST" IS_POST
Header set Cache-Control "no-cache" env=IS_POST
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postgresql COUNT(DISTINCT …) very slow
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You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
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How to access a preexisting collection with Mongoose?
...ctions of UserSchema and I want to give each one a different name Eg: users_server1, users_server2, users_server3...
– Ragnar
Jun 6 '14 at 20:41
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Best Practice: Access form elements by HTML id or name attribute?
...u are working with PHP, it's the name attribute that is your index in the $_POST global.
– seth
Mar 12 '10 at 20:56
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How to stop a JavaScript for loop?
... is a good approach. Thanks @T.J. Crowder
– techloris_109
Sep 13 '17 at 7:35
@T.J. Crowder which statement is a good a...
Rendering JSON in controller
...ting your own dogfood and doing both
In both cases render :json => some_data will JSON-ify the provided data. The :callback key in the second example needs a bit more explaining (see below), but it is another variation on the same idea (returning data in a way that JavaScript can easily handle....
Rails find_or_create_by more than one attribute?
There is a handy dynamic attribute in active-record called find_or_create_by:
5 Answers
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How to form tuple column from two columns in Pandas
...rtable with zip. It comes in handy when dealing with column data.
df['new_col'] = list(zip(df.lat, df.long))
It's less complicated and faster than using apply or map. Something like np.dstack is twice as fast as zip, but wouldn't give you tuples.
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