PMT Function

FUNCTION PA_GET_PMT_AMT(RATE     IN NUMBER,
                          AMT      IN NUMBER,
                          PAYMENTS IN NUMBER) RETURN NUMBER IS
    V_RATE    NUMBER := RATE;
    V_AMT     NUMBER := AMT;
    V_NOM     NUMBER := PAYMENTS;
    P_RATE_PM NUMBER := 0;
    P_NRATE   NUMBER := 0;
    P_VALR    NUMBER := 0;
    P_NVALR   NUMBER := 0;
    P_NVAL    NUMBER := 0;
    P_RETAMT  NUMBER := 0;
  BEGIN
    -- SELECT DECODE(V_RATE,0,1,V_RATE)INTO V_RATE FROM DUAL; 
    IF V_RATE > 0 THEN
      --Applied Ason 27-sep-2016
      P_RATE_PM := (+V_RATE / 12) / 100; --+1;
      P_NRATE   := (+P_RATE_PM) + 1;
      P_VALR    := ROUND(POWER(+P_NRATE, (V_NOM * -1)), 6);
      P_NVALR   := 1 - P_VALR;
      P_NVAL    := P_NVALR / P_RATE_PM;
      P_RETAMT  := ROUND(V_AMT / P_NVAL, 0);
    ELSE
      P_RETAMT := ROUND(V_AMT / V_NOM, 0);
    END IF;
    RETURN(P_RETAMT);
  END PA_GET_PMT_AMT;

SELECT PA_GET_PMT_AMT(12.5,50000,36) FROM DUAL;