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What's the difference between integer class and numeric class in R
...ouble precision floating point numbers) and integer. R will automatically convert between the numeric classes when needed, so for the most part it does not matter to the casual user whether the number 3 is currently stored as an integer or as a double. Most math is done using double precision, so ...
C/C++获取Windows的CPU、内存、硬盘使用率 - C/C++ - 清泛网 - 专注C/C++及内核技术
...us(&ms);
return ms.dwMemoryLoad;
}
2.获取Windows CPU使用率
__int64 CompareFileTime(FILETIME time1, FILETIME time2)
{
__int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime;
__int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime;
return (b - a);
}
//Win CPU使...
Clean ways to write multiple 'for' loops
...you need a three dimensional matrix, you define one:
class Matrix3D
{
int x;
int y;
int z;
std::vector<int> myData;
public:
// ...
int& operator()( int i, int j, int k )
{
return myData[ ((i * y) + j) * z + k ];
}
};
Or if you want to index using...
MFC中ComboBox控件的使用 - C/C++ - 清泛网 - 专注C/C++及内核技术
...)GetDlgItem(IDC_COMBO_CF))->ResetContent();//消除现有所有内容
for(int i=1;i<=100;i++)
{
strTemp.Format("%d",i);
((CComboBox*)GetDlgItem(IDC_COMBO_CF))->AddString(strTemp);
}
3，下拉的时候添加，如：
CString strTemp;
intiCount=((CComboBox*)GetDlgItem(IDC_COMBO_CF))->G...
How to map with index in Ruby?
What is the easiest way to convert
10 Answers
10
...
What's the difference between IQueryable and IEnumerable
...like LINQ-to-SQL to exist because they can parse the expression tree and convert it into equivalent SQL. And because the provider doesn't need to execute until the IQueryable is enumerated (it implements IEnumerable<T>, after all), it can combine multiple query operators (in the above exampl...
How do I clear the std::queue efficiently?
...wapping with an empty version of the container:
void clear( std::queue<int> &q )
{
std::queue<int> empty;
std::swap( q, empty );
}
It is also the only way of actually clearing the memory held inside some containers (std::vector)
...
What is this weird colon-member (“ : ”) syntax in the constructor?
...note the exceptions listed at the end of the FAQ entry).
The takeaway point from the FAQ entry is that,
All other things being equal, your code will run faster if you use initialization lists rather than assignment.
...
Vertical (rotated) label in Android
...ext context, AttributeSet attrs){
super(context, attrs);
final int gravity = getGravity();
if(Gravity.isVertical(gravity) && (gravity&Gravity.VERTICAL_GRAVITY_MASK) == Gravity.BOTTOM) {
setGravity((gravity&Gravity.HORIZONTAL_GRAVITY_MASK) | Gravity.TOP);
...
What should main() return in C and C++?
...ect (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments?
If int main() then return 1 or return 0 ?
...