Finding the implementation of a standard library function such as pow() is quite another matter. You will have to dig up the source code to your C standard runtime library and find the implementation in there. 查找标准库函数(如pow()的实现则是另一回事。您将不得不挖掘到C标准运行时...
xraised to the power ofy. Thepowfunction computesxraised to the power ofy. powdoes not recognize integral floating-point values greater than 264, such as 1.0E100. powhas an implementation that uses Streaming SIMD Extensions 2 (SSE2). See_set_SSE2_enablefor information and restrictions on usi...
ln(y)=n*ln(x) Then taking the exponential of both sides gives you what you want: y=exp(n*ln(x)) If you want something better, the best place I know to look isAbramowitz and Stegun.
Because C++ allows overloading, you can call any of the various overloads ofpow. In a C program, unless you're using the<tgmath.h>macro to call this function,powalways takes twodoublevalues and returns adoublevalue. If you use thepowmacro from<tgmath.h>, the type of the argument det...
4)Type-generic macro: If any argument has typelongdouble,powlis called. Otherwise, if any argument has integer type or has typedouble,powis called. Otherwise,powfis called. If at least one argument is complex or imaginary, then the macro invokes the corresponding complex function (cpowf,cpow...
Because C++ allows overloading, you can call any of the various overloads ofpow. In a C program, unless you're using the<tgmath.h>macro to call this function,powalways takes twodoublevalues and returns adoublevalue. If you use thepowmacro from<tgmath.h>, the type of the argument det...
I modified David's example by replacingReal.Math.powwith call to my own C functionc_powthat callspowfrommath.h. This shows exactly the same issue as David's example. Using gdb to inspect the FPU state before each call topowshows that the PC (Precision Control) bits of the x87 FPU con...
The pow() function sets errno to EDOM if the value of x is negative and y is non-integral. Pole Error The value of x is 0 and y is negative. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the divide-by-zero floating-point exception is raised. Range Er...
Thepowfunction computesxraised to the power ofy. powdoes not recognize integral floating-point values greater than 264, such as 1.0E100. powhas an implementation that uses Streaming SIMD Extensions 2 (SSE2). See_set_SSE2_enablefor information and restrictions on using the SSE2 implementation. ...
+y2 ) (function) pow(std::complex) complex power, one or both arguments may be a complex number (function template) pow(std::valarray) applies the functionstd::powto two valarrays or a valarray and a value (function template)