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Applying a function to every row of a table using dplyr?
...f Hadley's examples using pmap:
iris %>%
mutate(Max.Len= purrr::pmap_dbl(list(Sepal.Length, Petal.Length), max))
Using this approach, you can give an arbitrary number of arguments to the function (.f) inside pmap.
pmap is a good conceptual approach because it reflects the fact that when ...
Why is string concatenation faster than array join?
...tenation:
// ECMA-262, section 15.5.4.6
function StringConcat() {
if (IS_NULL_OR_UNDEFINED(this) && !IS_UNDETECTABLE(this)) {
throw MakeTypeError("called_on_null_or_undefined", ["String.prototype.concat"]);
}
var len = %_ArgumentsLength();
var this_as_string = TO_STRING_INLINE(t...
How do I parse a string to a float or int?
...
Python method to check if a string is a float:
def is_float(value):
try:
float(value)
return True
except:
return False
A longer and more accurate name for this function could be: is_convertible_to_float(value)
What is, and is not a float in Python may surpris...
Matplotlib make tick labels font size smaller
...lib figure, how can I make the font size for the tick labels using ax1.set_xticklabels() smaller?
10 Answers
...
Is it more efficient to copy a vector by reserving and copying, or by creating and swapping? [duplic
...VecFast(vec<int> original) // no reference
{
vector<int> new_;
new_.swap(original);
}
That would work, but an easier way is
vector<int> new_(original);
share
|
improve t...
how to clear the screen in python [duplicate]
... To avoid the 0 (system's return value) being shown, use absolutely_unused_variable = os.system("cls") or absolutely_unused_variable = os.system("clear")
– Shiva
Jul 4 '15 at 8:01
...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘c...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘class Derived*’ (source type is not polymorphic)在将父类型转换为子类型时,可以使用static_cast和dynamic_cast.如果使用dynamic_cast,它要求父类必须为多态的,即要求至少有一个虚函数,因此....
MFC的DDX和DDV技巧 - C/C++ - 清泛网 - 专注C/C++及内核技术
...件关系的成员变量的声明，代码：
// Dialog Data
//{{AFX_DATA(CMyDlg)
enum { IDD = IDD_DIALOG5 };
int m_edit;
//}}AFX_DATA
２． 在 .CPP文件中的类构造函数告终代码处，增加数据成员变量的一些初始化代码
CMyDlg::CMyDlg(CWnd* pParent )
...
Mismatch Detected for 'RuntimeLibrary'
...o++ library and the object file for the OP's program, and its value is "MDd_DynamicDebug" for one of them and "MTd_StaticDebug" for the other. This way, the linker that is trying to link two object files together can detect and report a whole new class of errors, given that the linkers that produced...
Android Studio inline compiler showing red errors, but compilation with gradle works fine
...ove-said steps, then the issue is resolved.
– hasnain_ahmad
May 10 '18 at 4:55
39
Deleting everyt...