大约有 15,000 项符合查询结果（耗时：0.0373秒） [XML]
Numpy: Divide each row by a vector element
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Here you go. You just need to use None (or alternatively np.newaxis) combined with broadcasting:
In [6]: data - vector[:,None]
Out[6]:
array([[0, 0, 0],
[0, 0, 0],
[0, 0, 0]])
In [7]: data / vector[:,None]
Out[7]:
array([[1, 1, 1],
[1, 1, 1],
[1, 1, 1]])
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Add one row to pandas DataFrame
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You can use df.loc[i], where the row with index i will be what you specify it to be in the dataframe.
>>> import pandas as pd
>>> from numpy.random import randint
>>> df = pd.DataFrame(columns=['lib', 'qty1', 'qty2'])
>>> for i in ra...
How to handle WndProc messages in WPF?
...in WPF using HwndSource and HwndSourceHook. See this thread on MSDN as an example. (Relevant code included below)
// 'this' is a Window
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
source.AddHook(new HwndSourceHook(WndProc));
private static IntPtr WndProc(IntPtr h...
Deserialize JSON into C# dynamic object?
...rialisation approach is suggested here. I modified the code slightly to fix a bug and suit my coding style. All you need is this code and a reference to System.Web.Extensions from your project:
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Obje...
DateTime.ToString(“MM/dd/yyyy HH:mm:ss.fff”) resulted in something like “09/14/2013 07.20.31.371”
...d of dot?
I'd suggest specifying CultureInfo.InvariantCulture:
string text = dateTime.ToString("MM/dd/yyyy HH:mm:ss.fff",
CultureInfo.InvariantCulture);
Alternatively, you could just quote the time and date separators:
string text = dateTime.ToString("MM'/'dd'/'...
How to sort a Ruby Hash by number value?
...it would not sort by string value... You should reverse a1 and a2 in your example
Best way in any case (as per Mladen) is:
metrics = {"sitea.com" => 745, "siteb.com" => 9, "sitec.com" => 10 }
metrics.sort_by {|_key, value| value}
# ==> [["siteb.com", 9], ["sitec.com", 10], ["sitea.co...
Big-oh vs big-theta [duplicate]
It seems to me like when people talk about algorithm complexity informally, they talk about big-oh. But in formal situations, I often see big-theta with the occasional big-oh thrown in.
I know mathematically what the difference is between the two, but in English, in what situation would using big-oh...
What is __declspec and when do I need to use it?
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This is a Microsoft specific extension to the C++ language which allows you to attribute a type or function with storage class information.
Documentation
__declspec (C++)
share...
Setting Icon for wpf application (VS 08)
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Assuming you use VS Express and C#.
The icon is set in the project properties page. To open it right click on the project name in the solution explorer. in the page that opens, there is an Application tab, in this tab you can set the icon.
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Asterisk in function call
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* is the "splat" operator: It takes a list as input, and expands it into actual positional arguments in the function call.
So if uniqueCrossTabs was [ [ 1, 2 ], [ 3, 4 ] ], then itertools.chain(*uniqueCrossTabs) is the same as saying itertools.chain([ 1, 2 ], [ 3, 4 ])
This is obv...