大约有 46,000 项符合查询结果（耗时：0.0546秒） [XML]
What's quicker and better to determine if an array key exists in PHP?
... if the value is NULL.
Whereas
isset() will return false if the key exist and value is NULL.
share
|
improve this answer
|
follow
|
...
How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
...
DateTime.strptime can handle seconds since epoch. The number must be converted to a string:
require 'date'
DateTime.strptime("1318996912",'%s')
share
|
...
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:
...
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...
How to get last inserted id?
...ofiles(UserId,GameId)
VALUES(@UserId, @GameId);
SELECT SCOPE_IDENTITY()
And then
Int32 newId = (Int32) myCommand.ExecuteScalar();
share
|
improve this answer
|
follow
...
iOS 7 TableView like in Settings App on iPad
...
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:...
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")...
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.
...
How do I list all versions of a gem available at a remote site?
... if you only want to look at that one, you could search for gem list ^rhc$ and the "--remote" and "--all" flags can be abbreviated and combined for gem list ^rhc$ -ra
– Joshua Cheek
Feb 5 '12 at 4:19
...
How to extract the decision rules from scikit-learn decision-tree?
...e output for a tree that is trying to return its input, a number between 0 and 10.
def tree(f0):
if f0 <= 6.0:
if f0 <= 1.5:
return [[ 0.]]
else: # if f0 > 1.5
if f0 <= 4.5:
if f0 <= 3.5:
return [[ 3.]]
else: # if f0 > 3.5
...