Revised version of exponentially fitted pseudo-Runge-Kutta method

In this paper, we have proposed the revised version of exponentially-fitted (ef) pseudo-Runge-Kutta method (ef-PRKM). The motivation behind the revision is to fill the leakage of error in the internal stages during the fitting process. Generally, the internal stage operator, in an ef-PRKM or ef-Runge-Kutta method (ef-RKM) integrates two exponential functions exp(+/- omega x), with unknown frequency omega epsilon R (for trigonometric-fitting exp(+/- omega x), omega epsilon iR). However, these internal stage operators produce some amount of errors in integrating other functions like x(k) exp(+/- omega x), k >= 0 . Here, we first measure the error expression and taking into account this error, we redefine the external stage (solution) operators and compute the revised weights of the ef-PRKM. The revised ef-PRKM is tested on two initial value problems (IVPs). The results are reported in tables and figure. The proposed method would be a good option to find the numerical solution of IVPs efficiently with less cost consumption in the form of slopes/function evaluations than the standard Runge-Kutta methods.