int main() {
FILE *in = fopen("task.in", "r");
FILE *out = fopen("task.out", "w");
int length = intScan(in);
int array[length];
arrayScan(in, array, length);
arrayAbs(array, length);
fclose(in);
arrayPrint(out, array, length);
fclose(out);
return 0;
}
int resistmean (float *in, int npix, float sigrej, float *mean,
float *sigmean, float *min, float *max) {
/* Arguments:
** in i: pointer to array of input values
** npix i: size of the input array
** sigrej i: the sigma level for pixel rejection
** mean o: mean value of unrejected pixels
** sigmean o: standard deviation of unrejected pixels
** (NOT the uncertainty or sigma of the mean)
** min o: minimum of input values
** max o: maximum of input values
*/
/* Local variables */
int i, j; /* loop indexes */
float median; /* median value of input array */
float *absdev; /* absolute deviation array */
float medabsdev; /* median of the absdev array */
float *tempdata; /* array of good pixel values */
float *tempdata2; /* array of good pixel values */
double sum; /* sum of pixel values */
float cutoff; /* value limitation */
int npix1, npix2; /* number of pixels in temp arrays */
/* Function definitions */
float findRMedian (float *, int ); /* compute median of array */
float findMean(float *, int ); /* compute mean of array */
float findSigma(float *, int , float *); /* compute stddev of array */
void arrayDiff(float *, float *, float , int ); /* subtract median */
void arrayAbs(float *,int); /* compute absolute value of array */
void wheregood(float *, float , int * ); /* flag outliers in array */
/* Initialize the counters and results */
npix1 = npix;
*mean = 0.;
*sigmean = 0.;
*min = 0;
*max = 0;
median = 0.;
medabsdev = 0.;
cutoff = 0.;
/* allocate temp arrays to store and manipulate the input array */
if (npix != 0) {
/* an array to store a copy of the data*/
tempdata = (float *) calloc(npix, sizeof(float));
if (tempdata == NULL) {
sprintf (MsgText, "Memory allocation failure in resistmean");
trlmessage (MsgText);
return (1);
}
/* and an array to store absolute deviation */
absdev = (float *) calloc(npix, sizeof(float));
if (absdev == NULL) {
sprintf (MsgText, "Memory allocation failure in resistmean");
trlmessage (MsgText);
return (1);
}
} else {
sprintf (MsgText, "Zero size array passed to resistmean");
trlerror (MsgText);
return (1);
}
/* Copy the input array, computing the initial sum, min, max */
sum = 0.;
*min = tempdata[0];
*max = tempdata[0];
for (i=0; i<npix1; i++) {
tempdata[i] = in[i];
sum += tempdata[i];
if (tempdata[i] < *min) *min = tempdata[i];
if (tempdata[i] > *max) *max = tempdata[i];
}
/* Compute the mean and median of the unrejected values */
*mean = (float) (sum/(double)npix1);
median = findRMedian (tempdata, npix1);
/* Subtract the median from every element in the array */
arrayDiff (tempdata, absdev, median, npix1);
/* Get the absolute value for each element in the resulting array */
arrayAbs (absdev, npix1);
/* Get the median of the absolute deviation array and divide by a
constant with some logic attached */
medabsdev = findRMedian (absdev, npix1) / 0.6745;
if (medabsdev < 1.0E-24)
medabsdev = findMean(absdev,npix1) / 0.8;
/* Compute the cutoff value in terms of the median absolute deviation */
cutoff = (sigrej) * medabsdev;
/* Flag values in the array that are beyond the cutoff */
wheregood (absdev, cutoff, &npix1);
/* Start a new temp array to populate with the good values;
npix1 should be the count of unrejected pixels here */
tempdata2 = (float *) calloc(npix1, sizeof(float));
if (tempdata2 == NULL) {
sprintf (MsgText, "Memory allocation failure in resistmean");
trlmessage (MsgText);
return (1);
}
/* Copy only the good values into the new temp array.
npix is still the number of original input values, while npix1
is now the number of remaining good values. */
j=0;
for (i=0; i<npix; i++) {
if (absdev[i] != PFLAG) {
tempdata2[j]=tempdata[i];
j++;
}
}
/************ ROUND 2 ***********/
/* Compute the mean and stddev of the values in the new array */
*mean = findMean(tempdata2, npix1);
*sigmean = findSigma(tempdata2, npix1, mean);
/* Compensate sigma for truncation and compute new cutoff */
if (sigrej <= 4.5) {
*sigmean = *sigmean / (-0.15405+0.90723*sigrej - 0.23584*sigrej*sigrej+0.020142*sigrej*sigrej*sigrej);
}
cutoff = sigrej * (*sigmean);
/* Reinitialize the absdev array to hold new set of values */
free(absdev); /* clear the old array */
absdev = (float *) calloc(npix1, sizeof(float));
if (absdev == NULL) {
sprintf (MsgText, "Memory allocation failure in resistmean");
return (1);
}
/* Find the median of the good values. */
median = findRMedian(tempdata2, npix1);
/* Subtract the median from every element in the array */
arrayDiff (tempdata2, absdev, median, npix1);
/* Get the absolute value for each element in the resulting array */
arrayAbs (absdev, npix1);
/* Get the median of the absolute deviation array */
medabsdev = findRMedian(absdev, npix1) / 0.6745;
if (medabsdev < 1.0E-24)
medabsdev = findMean(absdev, npix1) / 0.8;
/* Flag values in the array that are beyond the new cutoff */
npix2 = npix1;
wheregood(absdev, cutoff, &npix2);
/* Start a new temp array to populate with just the final good values */
free (tempdata); /* free the previous copy */
tempdata = (float *) calloc(npix2, sizeof(float));
if (tempdata == NULL) {
sprintf (MsgText, "Memory allocation failure in resistmean");
return (1);
}
/* Copy only the good values to the new array */
j=0;
for (i=0; i<npix1; i++) {
if (absdev[i] != PFLAG) {
tempdata[j] = tempdata2[i];
j++;
}
}
/* Compute the mean and stddev of the latest array of good values */
*mean = findMean (tempdata, npix2);
*sigmean = findSigma(tempdata, npix2, mean);
/* Compensate sigma for truncation :*/
if (sigrej <= 4.5) {
*sigmean = *sigmean / (-0.15405+0.90723*sigrej-0.23584*sigrej*sigrej+0.020142*sigrej*sigrej*sigrej);
}
/* Free all local arrays */
free(absdev);
free(tempdata);
free(tempdata2);
return (0); /* Successful return */
}
