Maths › Rootfinding ›

# Falseposition

Calculates the zeros of a function using the Regula-Falsi method.

Controller: **CodeCogs**

## Interface

C++

## Falseposition

doublefalseposition( | double | (*f)(double)[function pointer] | |

double | x0` = -1E+7` | ||

double | x1` = 1E+7` | ||

double | eps` = 1E-10` | ||

double | maxit` = 1000` | ) |

*f*starting with an initial interval

*[x0, x1]*and iterating the sequence above until either the accuracy

*eps*is achieved or the maximum number of iterations

*maxit*is exceeded.

## Example:

#include <codecogs/maths/rootfinding/falseposition.h> #include <iostream> #include <iomanip> #include <cmath> // user-defined function double f(double x) { return cos(x); } int main() { double x = Maths::RootFinding::falseposition(f, 1, 3); std::cout << "The calculated zero is X = " << std::setprecision(12) << x << std::endl; std::cout << "The associated ordinate value is Y = " << f(x) << std::endl; return 0; }Output:

The calculated zero is X = 1.70614146372 The associated ordinate value is Y = -0.134932299622

## References:

- Jean-Pierre Moreau's Home Page, http://perso.wanadoo.fr/jean-pierre.moreau/
- F.R. Ruckdeschel, "BASIC Scientific Subroutines", Vol. II, BYTE/McGRAWW-HILL, 1981

### Parameters

f the user-defined function x0 Default value = -1E+7 x1 Default value = 1E+7 eps Default value = 1E-10 maxit Default value = 1000

### Authors

*Lucian Bentea (August 2005)*

##### Source Code

Source code is available when you buy a Commercial licence.

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