大约有 46,000 项符合查询结果(耗时:0.0433秒) [XML]
Cluster analysis in R: determine the optimal number of clusters
					..., calinski.best, "\n")
# 5 clusters!
Four. Determine the optimal model and number of clusters according to the Bayesian Information Criterion for expectation-maximization, initialized by hierarchical clustering for parameterized Gaussian mixture models
# See http://www.jstatsoft.org/v18/i06/pap...				
				
				
							How to normalize a NumPy array to within a certain range?
					...io /= np.max(np.abs(audio),axis=0)
image *= (255.0/image.max())
Using /= and *= allows you to eliminate an intermediate temporary array, thus saving some memory.  Multiplication is less expensive than division, so 
image *= 255.0/image.max()    # Uses 1 division and image.size multiplications
i...				
				
				
							Modifying a subset of rows in a pandas dataframe
					Assume I have a pandas DataFrame with two columns, A and B. I'd like to modify this DataFrame (or create a copy) so that B is always NaN whenever A is 0. How would I achieve that?
                    
                    
                        
                            
                 ...				
				
				
							Calculate the center point of multiple latitude/longitude coordinate pairs
					Given a set of latitude and longitude points, how can I calculate the latitude and longitude of the center point of that set (aka a point that would center a view on all points)?
                    
                    
                        
                            
                  ...				
				
				
							The simplest possible JavaScript countdown timer? [closed]
					...
        
        
    
    
I have two demos, one with jQuery and one without. Neither use date functions and are about as simple as it gets.
Demo with vanilla JavaScript
function startTimer(duration, display) {
    var timer = duration, minutes, seconds;
    setInterval(functio...				
				
				
							GroupBy pandas DataFrame and select most common value
					... two. To clean the data I have to group by data frame by first two columns and select most common value of the third column for each combination.
                    
                    
                        
                            
                                
                 ...				
				
				
							Initialising an array of fixed size in python [duplicate]
					...ets the requirements of the question because you have a defined size array and you can index one of the five elements without getting an IndexError.  This is the closest thing to the C expression.
                
– user2233706
                Oct 26 '14 at 17:43
            
        
    
...				
				
				
							How do I generate random numbers in Dart?
					How do I generate random numbers using Dart?
                    
                    
                        
                            
                                
                                        13 Answers
                                    13
                          ...				
				
				
							How to stop app that node.js express 'npm start'
					...
npm help npm-scripts
  prestop, stop, poststop: Run by the npm stop command.
Set one of the above in your package.json, and then use npm stop
npm help npm-stop
You can make this really simple if you set in app.js,
  process.title = myApp;
And, then in scripts.json,
"scripts": {
    "star...				
				
				
							Check that an email address is valid on iOS [duplicate]
					...rict - http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/
And because categories are just better, you could also add an interface:
@interface NSString (emailValidation) 
  - (BOOL)isValidEmail;
@end
Implement
@implementation NSString (emailValidation)
-(BOOL)isValidEmail
{
  BOO...				
				
				
							