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How to initialize a vector in C++ [duplicate]
...is with an array:
int vv[2] = { 12,43 };
std::vector<int> v(&vv[0], &vv[0]+2);
Or, for the case of assignment to an existing vector:
int vv[2] = { 12,43 };
v.assign(&vv[0], &vv[0]+2);
Like James Kanze suggested, it's more robust to have functions that give you the beginni...
isset() and empty() - what to use
...mpty checks if the variable is set and if it is it checks it for null, "", 0, etc
Isset just checks if is it set, it could be anything not null
With empty, the following things are considered empty:
"" (an empty string)
0 (0 as an integer)
0.0 (0 as a float)
"0" (0 as a string)
NULL
FALSE
array(...
How to print a string in fixed width?
...
EDIT 2013-12-11 - This answer is very old. It is still valid and correct, but people looking at this should prefer the new format syntax.
You can use string formatting like this:
>>> print '%5s' % 'aa'
aa
>>>...
How to get overall CPU usage (e.g. 57%) on Linux [closed]
...ke a look at cat /proc/stat
grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'
EDIT please read comments before copy-paste this or using this for any serious work. This was not tested nor used, it's an idea for people who do not want to install a utility or for so...
What are “named tuples” in Python?
...xcept that they are immutable. They were added in Python 2.6 and Python 3.0, although there is a recipe for implementation in Python 2.4.
For example, it is common to represent a point as a tuple (x, y). This leads to code like the following:
pt1 = (1.0, 5.0)
pt2 = (2.5, 1.5)
from math import s...
Using NumberPicker Widget with Strings
...
NumberPicker picker = new NumberPicker(this);
picker.setMinValue(0);
picker.setMaxValue(2);
picker.setDisplayedValues( new String[] { "Belgium", "France", "United Kingdom" } );
share
|
im...
Fill between two vertical lines in matplotlib
...
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.plot(range(20))
ax.axvspan(8, 14, alpha=0.5, color='red')
plt.show()
You could use fill_betweenx to do this, but the extents (both x and y) of the rectangle would be in data coordinates. With axvspan, the y-extents of the rectangle...
Boost.Asio的简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术
...来演示timer到时了.
std::cout << "Hello, world! ";
return 0;
}
完整的代码:
#include <iostream>
#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
int main()
{
boost::asio::io_service io;
boost::asio::deadline_timer t(io, boost:...
Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
...
As Sven mentioned, x[[[0],[2]],[1,3]] will give back the 0 and 2 rows that match with the 1 and 3 columns while x[[0,2],[1,3]] will return the values x[0,1] and x[2,3] in an array.
There is a helpful function for doing the first example I gave, n...
How do you read CSS rule values with JavaScript?
...(className) {
var cssText = "";
var classes = document.styleSheets[0].rules || document.styleSheets[0].cssRules;
for (var x = 0; x < classes.length; x++) {
if (classes[x].selectorText == className) {
cssText += classes[x].cssText || classes[x].style.cssText...