# include <dvo.h>
# define MAX_ORDER 3

/**** XXXX warning: these functions have not been corrected to handle 
      the change of Mcal from millimags to mags
      I don't think most functions are using the Mcal polynomial terms in 
      any case... ****/

/* all terms of order > 0 are stored as 16bit floats 
   the zero-order term is stored as a short int (-32k,+32k) */

/* convert double to low-precision short int */
short int putMi (double value) {
  
  double T;
  unsigned int I;

  if (value > 0) {
    T = 1000 * log10 (value);
    I = MAX (MIN (T, 16383), -16382) + 0x3fff;
    return (I);
  }
  if (value < 0) {
    T = -value;
    T = 1000 * log10 (T);
    I = MAX (MIN (T, 16383), -16382) + 0xbfff;
    return (I);
  }
  if (value == 0) {
    I = 0;
    return (0);
  }
  return (NO_MAG);
}

/* convert low-precision short int to double */
double getMi (short int value) {
  
  double T, V, sign;
  short int I;

  if (value == 0) {
    return (0.0);
  }
  if (value & 0x8000) {
    sign = -1;
    I = value & 0x7fff;
  } else {
    sign = +1;
    I = value;
  }
    
  T = (I - 0x3fff) / 1000.0;
  V = sign * pow (10.0, T);
  return (V);
}

/* convert image parameters to c[i] coeffs */
void returnMcal (Image *image, double *c) {

  switch (image[0].order) {
  case 0:
    c[0] = image[0].Mcal;
    return;
  case 1:
    c[0] = image[0].Mcal;
    c[1] = getMi (image[0].Mx);
    c[2] = getMi (image[0].My);
    return;
  case 2:
    c[0] = image[0].Mcal;
    c[1] = getMi (image[0].Mx);
    c[2] = getMi (image[0].Mxx);
    c[3] = getMi (image[0].My);
    c[4] = getMi (image[0].Mxy);
    c[5] = getMi (image[0].Myy);
    return;
  case 3:
    c[0] = image[0].Mcal;
    c[1] = getMi (image[0].Mx);
    c[2] = getMi (image[0].Mxx);
    c[3] = getMi (image[0].Mxxx);
    c[4] = getMi (image[0].My);
    c[5] = getMi (image[0].Mxy);
    c[6] = getMi (image[0].Mxxy);
    c[7] = getMi (image[0].Myy);
    c[8] = getMi (image[0].Mxyy);
    c[9] = getMi (image[0].Myyy);
    return;
  case 4:
    c[0] = image[0].Mcal;
    c[1] = getMi (image[0].Mx);
    c[2] = getMi (image[0].Mxx);
    c[3] = getMi (image[0].Mxxx);
    c[4] = getMi (image[0].Mxxxx);
    c[5] = getMi (image[0].My);
    c[6] = getMi (image[0].Mxy);
    c[7] = getMi (image[0].Mxxy);
    c[8] = getMi (image[0].Mxxxy);
    c[9] = getMi (image[0].Myy);
    c[10] = getMi (image[0].Mxyy);
    c[11] = getMi (image[0].Mxxyy);
    c[12] = getMi (image[0].Myyy);
    c[13] = getMi (image[0].Mxyyy);
    c[14] = getMi (image[0].Myyyy);
    return;
  default:
    c[0] = 0;
    return;
  }
}

void assignMcal (Image *image, double *c, int order) {

  image[0].order = order;

  switch (order) {
  case 0:
    image[0].Mcal = c[0];
    return;
  case 1:
    image[0].Mcal = c[0];
    image[0].Mx    = putMi(c[1]);
    image[0].My    = putMi(c[2]);
    return;
  case 2:
    image[0].Mcal = c[0];
    image[0].Mx    = putMi(c[1]);
    image[0].Mxx   = putMi(c[2]);
    image[0].My    = putMi(c[3]);
    image[0].Mxy   = putMi(c[4]);
    image[0].Myy   = putMi(c[5]);
    return;
  case 3:
    image[0].Mcal = c[0];
    image[0].Mx    = putMi(c[1]);
    image[0].Mxx   = putMi(c[2]);
    image[0].Mxxx  = putMi(c[3]);
    image[0].My    = putMi(c[4]);
    image[0].Mxy   = putMi(c[5]);
    image[0].Mxxy  = putMi(c[6]);
    image[0].Myy   = putMi(c[7]);
    image[0].Mxyy  = putMi(c[8]);
    image[0].Myyy  = putMi(c[9]);
    return;
  case 4:
    image[0].Mcal = c[0];
    image[0].Mx    = putMi(c[1]);
    image[0].Mxx   = putMi(c[2]);
    image[0].Mxxx  = putMi(c[3]);
    image[0].Mxxxx = putMi(c[4]);
    image[0].My    = putMi(c[5]);
    image[0].Mxy   = putMi(c[6]);
    image[0].Mxxy  = putMi(c[7]);
    image[0].Mxxxy = putMi(c[8]);
    image[0].Myy   = putMi(c[9]);
    image[0].Mxyy  = putMi(c[10]);
    image[0].Mxxyy = putMi(c[11]);
    image[0].Myyy  = putMi(c[12]);
    image[0].Mxyyy = putMi(c[13]);
    image[0].Myyyy = putMi(c[14]);
    return;
  default:
    image[0].Mcal = 0.0;
    image[0].order = 0;
    return;
  }
}

/* return value of image fit at x,y */
double applyMcal (Image *image, double x, double y) {

  double Mcal, c[15];

  returnMcal (image, c);  /* convert image parameters to c[i] coeffs */
  Mcal = 0.0;
  switch (image[0].order) {
  case 0:
    Mcal = c[0];
    break;
  case 1:
    Mcal = c[0] + x*c[1] + y*c[2];
    break;
  case 2:
    Mcal = c[0] + x*(c[1] + x*c[2]) + y*(c[3] + x*c[4] + y*c[5]);
    break;
  case 3:
    Mcal = c[0] + x*(c[1] + x*(c[2] + x*c[3])) + y*(c[4] + x*(c[5] + x*c[6]) + y*(c[7] + x*c[8] + y*c[9]));
    break;
  case 4:
    Mcal = c[0] + x*(c[1] + x*(c[2] + x*(c[3] + x*c[4]))) + y*(c[5] + x*(c[6] + x*(c[7] + x*c[8])) + y*(c[9] + x*(c[10] + x*c[11]) + y*(c[12] + x*c[13] + y*c[14])));
    break;
  }
  return (Mcal);
}

double findscatter (double *X, double *Y, double *M, double *dM, int N, double *c, int order) {
  
  int i;
  double *x, *y, *m, *dm;
  double S, S2, s, dS;

  S2 = S = 0;
  if (N < 2) {
    return (0.0);
  }
  
  x = X; y = Y; m = M; dm = dM;
  switch (order) {
  case 0:
    for (i = 0; i < N; i++, m++, dm++) {
      dS  = *m - c[0];
      *dm = dS;
      S  += dS;
      S2 += dS*dS;
    }
    break;
  case 1:
    for (i = 0; i < N; i++, m++, x++, y++, dm++) {
      s   = c[0] + *x*c[1] + *y*c[2];
      dS  = *m - s;
      *dm = dS;
      S  += dS;
      S2 += dS*dS;
    }
    break;
  case 2:
    for (i = 0; i < N; i++, m++, x++, y++, dm++) {
      s   = c[0] + *x*(c[1] + *x*c[2]) + *y*(c[3] + *x*c[4] + *y*c[5]);
      dS  = *m - s;
      *dm = dS;
      S  += dS;
      S2 += dS*dS;
    }
    break;
  case 3:
    for (i = 0; i < N; i++, m++, x++, y++, dm++) {
      s   = c[0] + *x*(c[1] + *x*(c[2] + *x*c[3])) + *y*(c[4] + *x*(c[5] + *x*c[6]) + *y*(c[7] + *x*c[8] + *y*c[9]));
      dS  = *m - s;
      *dm = dS;
      S  += dS;
      S2 += dS*dS;
    }
    break;
  case 4:
    for (i = 0; i < N; i++, m++, x++, y++, dm++) {
      s   = c[0] + *x*(c[1] + *x*(c[2] + *x*(c[3] + *x*c[4]))) + *y*(c[5] + *x*(c[6] + *x*(c[7] + *x*c[8])) + *y*(c[9] + *x*(c[10] + *x*c[11]) + *y*(c[12] + *x*c[13] + *y*c[14])));
      dS  = *m - s;
      *dm = dS;
      S  += dS;
      S2 += dS*dS;
    }
    break;
  }
  S = S / N;
  S2 = sqrt (S2 / N - S*S);
  return (S2);
}
