double DigFil(invar, initval, setic)
double invar, initval; int setic;
/******************************************************************************/
/* Filter Solutions Version 2009                 Nuhertz Technologies, L.L.C. */
/*                                                            www.nuhertz.com */
/*                                                            +1 602-279-2448 */
/* 6th Order Low Pass Chebyshev II                                            */
/* Bilinear Transformation with no Prewarping                                 */
/* Sample Frequency = 800.0 Hz                                                */
/* Cascade Form                                                               */
/* Arithmetic Precision = 8 Digits                                            */
/*                                                                            */
/* Pass Band Frequency = 500.0 mHz                                            */
/* Pass Band Attenuation = 3.010 dB                                           */
/*                                                                            */
/* Stop Band Ratio = 4                                                        */
/* Stop Band Frequency = 2.000 Hz                                             */
/* Stop Band Attenuation = 101.5 dB                                           */
/* Equalization Order = 1,  Equalized to 5 dB                                 */
/*                                                                            */
/******************************************************************************/
/*                                                                            */
/* Input Variable Definitions:                                                */
/* Inputs:                                                                    */
/*   invar    double      The input to the filter                             */
/*   initvar  double      The initial value of the filter                     */
/*   setic    int         1 to initialize the filter to the value of initvar  */
/*                                                                            */
/* Option Selections:                                                         */
/* Standard C;   Initializable;            Internal States;   Optimized;      */
/*                                                                            */
/* There is no requirement to ever initialize the filter.                     */
/* The default initialization is zero when the filter is first called         */
/*                                                                            */
/******************************************************************************/
/*                                                                            */
/* This software is automatically generated by Filter Solutions               */
/* no restrictions from Nuhertz Technologies, L.L.C. regarding the use and    */
/* distributions of this software.                                            */
/*                                                                            */
/******************************************************************************/

{
    double sumnum=0.0, sumden=0.0, newin=0.0; int i=0, j=0, iz=0;
    static double states[4][2] = {
        {0.0,0.0},
        {0.0,0.0},
        {0.0,0.0},
        {0.0,0.0}
    };
    static double znum[4][2] = {
        {1.0,-1.99632},
        {1.0,-1.9995066},
        {1.0,-1.9997356},
        {-1.0023878,1.0}
    };
    static double zden[4][2] = {
        {.99222992,-1.9922136},
        {.99446461,-1.9944487},
        {.99802545,-1.99801},
        {-.9976179,1.0}
    };
    if (setic==1){
        for (j=0;j<2;j++) states[0][j] = j] = j] =*initval;
        for (j=0;j<2;j++) states[1][j] = j] = j] = *initval;
        for (j=0;j<2;j++) states[2][j] = j] = j] = *initval;
        for (j=0;j<1;j++) states[3][j] = j] = j] = *initval;
        return initval;
    }
    else{
        newin = invar*-8.3241881e-06;
        for (i=0;i<4;i++){
            sumnum = sumden = 0.0;  iz=(i==3?1:2);
            for (j=0;j<iz;j++){
                sumden += states[i][j]*zden[i][j];
                sumnum += states[i][j]*znum[i][j];
                if (j<iz-1) states[i][j] = states[i][j+1];
            }
            states[i][iz-1] = (newin-sumden);
            sumnum += states[i][iz-1];
            newin = sumnum;
        }
        return newin;
    }
}