大约有 16,000 项符合查询结果（耗时：0.0283秒） [XML]
Linear Regression and group by in R
I want to do a linear regression in R using the lm() function. My data is an annual time series with one field for year (22 years) and another for state (50 states). I want to fit a regression for each state so that at the end I have a vector of lm responses. I can imagine doing for loop for each ...
How to perform a mysqldump without a password prompt?
...
Since you are using Ubuntu, all you need to do is just to add a file in your home directory and it will disable the mysqldump password prompting. This is done by creating the file ~/.my.cnf (permissions need to be 600).
Add this to the .my.cn...
Why does Math.round(0.49999999999999994) return 1?
...
Summary
In Java 6 (and presumably earlier), round(x) is implemented as floor(x+0.5).1 This is a specification bug, for precisely this one pathological case.2 Java 7 no longer mandates this broken implementation.3
The problem
0.5+0.49999999999999994 i...
Is an entity body allowed for an HTTP DELETE request?
When issuing an HTTP DELETE request, the request URI should completely identify the resource to delete. However, is it allowable to add extra meta-data as part of the entity body of the request?
...
Reading a binary file with python
I find particularly difficult reading binary file with Python. Can you give me a hand?
I need to read this file, which in Fortran 90 is easily read by
...
Trigger 404 in Spring-MVC controller?
...esponseStatus annotation:
@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
...
}
@Controller
public class SomeController {
@RequestMapping.....
public void handleCall() {
if (isFound()) {
// whatever
...
How to print a stack trace in Node.js?
...
Any Error object has a stack member that traps the point at which it was constructed.
var stack = new Error().stack
console.log( stack )
or more simply:
console.trace("Here I am!")
...
How do I access properties of a javascript object if I don't know the names?
Say you have a javascript object like this:
8 Answers
8
...
Is there a Python caching library?
I'm looking for a Python caching library but can't find anything so far. I need a simple dict -like interface where I can set keys and their expiration and get them back cached. Sort of something like:
...
How to remove duplicate values from a multi-dimensional array in PHP
...
Here is another way. No intermediate variables are saved.
We used this to de-duplicate results from a variety of overlapping queries.
$input = array_map("unserialize", array_unique(array_map("serialize", $input)));
...