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How to track down a “double free or corruption” error
...You can set this from gdb by using the set environment MALLOC_CHECK_ 2 command before running your program; the program should abort, with the free() call visible in the backtrace.
see the man page for malloc() for more information
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JSON left out Infinity and NaN; JSON status in ECMAScript?
Any idea why JSON left out NaN and +/- Infinity? It puts Javascript in the strange situation where objects that would otherwise be serializable, are not, if they contain NaN or +/- infinity values.
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How to get last inserted id?
...ofiles(UserId,GameId)
VALUES(@UserId, @GameId);
SELECT SCOPE_IDENTITY()
And then
Int32 newId = (Int32) myCommand.ExecuteScalar();
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Difference between declaring variables before or in loop?
...etter, a or b?
From a performance perspective, you'd have to measure it. (And in my opinion, if you can measure a difference, the compiler isn't very good).
From a maintenance perspective, b is better. Declare and initialize variables in the same place, in the narrowest scope possible. Don't leave...
iOS 7 TableView like in Settings App on iPad
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I've gone ahead and further customized the willDisplayCell to get a better simulation of the cell styles in the settings app.
Objective-C
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:...
How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
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DateTime.strptime can handle seconds since epoch. The number must be converted to a string:
require 'date'
DateTime.strptime("1318996912",'%s')
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Moving matplotlib legend outside of the axis makes it cutoff by the figure box
... np.cos(x), label='Cosine')
ax.plot(x, np.arctan(x), label='Inverse tan')
handles, labels = ax.get_legend_handles_labels()
lgd = ax.legend(handles, labels, loc='upper center', bbox_to_anchor=(0.5,-0.1))
text = ax.text(-0.2,1.05, "Aribitrary text", transform=ax.transAxes)
ax.set_title("Trigonometry")...
pandas dataframe columns scaling with sklearn
I have a pandas dataframe with mixed type columns, and I'd like to apply sklearn's min_max_scaler to some of the columns. Ideally, I'd like to do these transformations in place, but haven't figured out a way to do that yet. I've written the following code that works:
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Is std::vector so much slower than plain arrays?
...d::vector is "implemented as an array," blah blah blah. Today I went down and tested it, and it seems to be not so:
22 Ans...
Efficient way to determine number of digits in an integer
...1; if (x < 100) return 2; etc., so that the function will do less tests and exit faster.
– squelart
Sep 28 '09 at 23:44
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