pow

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 7 years ago . I got curious about the way power calculation is done in Java and the performance of available methods. So I wrote a simple test to check on Math.pow() , * and ^ operations. public static void main(String[] args)

问题 This question already has answers here : Cannot implicitly convert type 'double' to 'long' (6 answers) Closed 6 years ago . I have a constructor that returns the result of two ints with a 'to the power of' operator. I am trying to use the math.pow method to do this but im not to sure how it work. Here is my constructor public int Power (int firstNumber, int secondNumber) { result = Math.Pow(firstNumber, secondNumber); return result; } and the code that calls it case "^": result = application

问题 #include <iostream> #include <string.h> using namespace std; int main() { int e=0; int b=0; cout<<"Enter Exponent"; cin>>e; cout<<"Enter Base"; cin>>b; pow(e, b); cout<<"Power:"<<e; return 0; } void pow(int e, int b) { int t=1; while(b==t) { e=e*b; t++; } } Here is the error I received: ulaga.cpp|29|error: 'pow' was not declared in this scope Can any one explain why this error occurred? 回答1: The C++ compiler parses through your code file sequentially in order. i.e. line 1 then line 2 then

问题 #include <iostream> #include <string.h> using namespace std; int main() { int e=0; int b=0; cout<<"Enter Exponent"; cin>>e; cout<<"Enter Base"; cin>>b; pow(e, b); cout<<"Power:"<<e; return 0; } void pow(int e, int b) { int t=1; while(b==t) { e=e*b; t++; } } Here is the error I received: ulaga.cpp|29|error: 'pow' was not declared in this scope Can any one explain why this error occurred? 回答1: The C++ compiler parses through your code file sequentially in order. i.e. line 1 then line 2 then

问题 I'm trying to write something small in Kotlin and I'm having problems with finding the second power of a Double number. According to this, Double should implement a pow function receiving another Double , but when I try using this method I get Unresolved reference: pow and an error. Here's my sample code: fun main() { val d: Double = 1.1; val d2: Double = d.pow(2.0); // Here's the error, on the token 'pow'. println(d2); } I can't find any reason to this. This feature is only from Kotlin 1.2,

问题 I am trying to impliment RSA encryption scheme. It goes something like this: encrypted data = ((message)^e) % n and decrypted data = ((encrypted data)^d) % n I tried to implement this in c. Here is the code : #include <stdio.h> #include <stdlib.h> #include <math.h> int main(){ long int num = 3255859; long int encrypt =(int)pow((double) num,3) % 33; printf("%ld\n",encrypt); return 0; } I compiled this using gcc -Werror -g -o encrypt encrypt.c -lm This is the output I get = -2 , which is

问题 Why is the output of the dResult invalid ? Env: Visual Studio 2008 int _tmain(int argc, _TCHAR* argv[]) { double dN = - 0.091023604111478473 ; double dD = 0.127777777777777; double dResult = pow( dN,dD ); //dResult = -1.#IND000000000000 return 0; } 回答1: See http://www.cplusplus.com/reference/clibrary/cmath/pow/ double pow (double base, double exponent ); "If base is negative and exponent is not an integral value, or if base is zero and exponent is negative, a domain error occurs, setting the

问题 I have a small bit of code: #include <math.h> int main(void){ pow(2.0,7.0); //Works double x = 3.0; pow(2.0,x); //Fails with error "undefined reference to 'pow'" return 0; } I have linked -lm in my Eclipse compiler settings: gcc -O0 -g3 -Wall -lm -c -fmessage-length=0 -MMD -MP -MF"src/pgm.d" -MT"src/pgm.d" -o "src/pgm.o" "../src/pgm.c" , so I'm not sure what the source of the error is. What am I not doing corectly? 回答1: Put -lm to the end of the command line. 回答2: Your -lm option doesn't work

问题 Given a vector of reals c and a vector of integers rw , I want to create a vector z with elements z_i=c_i^rw_i . I tried to do this using the component-wise function pow , but I get a compiler error. #include <Eigen/Core> typedef Eigen::VectorXd RealVector; typedef Eigen::VectorXi IntVector; // dynamically-sized vector of integers RealVector c; c << 2, 3, 4, 5; IntVector rw; rw << 6, 7, 8, 9; RealVector z = c.pow(rw); **compile error** The compiler error is error C2664: 'const Eigen:

问题 Having perused the MSDN documentation for both the ^ (hat) operator and the Math.Pow() function, I see no explicit difference. Is there one? There obviously is the difference that one is a function while the other is considered an operator, e.g. this will not work: Public Const x As Double = 3 Public Const y As Double = Math.Pow(2, x) ' Fails because of const-ness But this will: Public Const x As Double = 3 Public Const y As Double = 2^x But is there a difference in how they produce the end