大约有 47,000 项符合查询结果（耗时：0.0556秒） [XML]
What Haskell representation is recommended for 2D, unboxed pixel arrays with millions of pixels?
...
Finally, my arrays are two-dimensional. I suppose I could deal with the extra indirection imposed by a representation as "array of arrays" (or vector of vectors), but I'd prefer an abstraction that has index-mapping support. Can anyone recommend anything from a standard library or from Hackage?
...
Numpy - add row to array
...2, 0]])
X = array([[0, 1, 2], [1, 2, 0], [2, 1, 2], [3, 2, 0]])
add to A all rows from X where the first element < 3:
import numpy as np
A = np.vstack((A, X[X[:,0] < 3]))
# returns:
array([[0, 1, 2],
[0, 2, 0],
[0, 1, 2],
[1, 2, 0],
[2, 1, 2]])
...
Get notified when UITableView has finished asking for data?
...eload its data. So, when the second NSLog is fired, the table view has actually finish asking for data.
I've subclassed UITableView to send methods to the delegate before and after reloadData. It works like a charm.
share
...
What is the pythonic way to avoid default parameters that are empty lists?
...he preferred way in this example is to say: if working_list is None . The caller might have used an empty list-like object with a custom append.
– tzot
Dec 14 '08 at 12:45
5
...
find vs find_by vs where
...
Use whichever one you feel suits your needs best.
The find method is usually used to retrieve a row by ID:
Model.find(1)
It's worth noting that find will throw an exception if the item is not found by the attribute that you supply. Use where (as described below, which will return an empty arr...
How to check size of a file using Bash?
...
[ -n file.txt ] doesn't check its size, it checks that the string file.txt is non-zero length, so it will always succeed.
If you want to say "size is non-zero", you need [ -s file.txt ].
To get a file's size, you can use wc -c to get the size (file length) in bytes:
file=file.txt
...
What's an elegant way to conditionally add a class to an HTML element in a view?
...classes mixed with default classes, then you need to put that logic into a string interpolation or ERB tag.
Here's an updated approach that avoids putting any logic into the views:
<div class="<%= class_string(ok: @success) %>">
some message here
</div>
class_string method
...
How to wait for a BackgroundWorker to cancel?
...Async();
_resetEvent.WaitOne(); // will block until _resetEvent.Set() call made
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
while(!e.Cancel)
{
// do something
}
_resetEvent.Set(); // signal that worker is done
}
...
How to debug JavaScript / jQuery event bindings with Firebug or similar tools?
...ked!') }"
})
See jQuery.fn.data (where jQuery stores your handler internally).
jQuery 1.8.x
var clickEvents = $._data($('#foo')[0], "events").click;
jQuery.each(clickEvents, function(key, handlerObj) {
console.log(handlerObj.handler) // prints "function() { console.log('clicked!') }"
})
...
Detect permission of camera in iOS
...
Check the AVAuthorizationStatus and handle the cases properly.
NSString *mediaType = AVMediaTypeVideo;
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];
if(authStatus == AVAuthorizationStatusAuthorized) {
// do your logic
} else if(authStatus...