source: branches/alilink/GDE/SUPPORT/varpos.c

#include <stdlib.h>
#include "Flatio.c"
#define MAX(a,b) ((a)>(b)?(a):(b))
 
/*
*       Varpos.c- An extremely simple program for showing which positions
*       are varying in an alignment.  Use this as a model for other
*       external functions.
*
*       Read in a flat file alignment, pass back an alignment color
*       mask.
* 
*       Copyright 1991/1992 Steven Smith, Harvard Genome lab. 
* 
*/ 

main(ac,av)
int ac;  
char **av; 
{
        struct data_format data[10000];
        int i,j,k,numseqs,rev = FALSE;
        int maxlen = -99999,
        score = 0,
        minoffset = 99999;
        char ch; 
        if(ac>2) 
        {
                fprintf(stderr,"Usage %s [-rev]<gde_flat_file>gde_color_mask\n",                av[0]); 
                exit(1); 
        } 
        if(ac == 2)
                if(strcmp(av[1],"-rev") == 0) 
                        rev = TRUE;

        numseqs = ReadFlat(stdin,data,10000);

        if(numseqs == 0)
                exit(1);

        for(j=0;j<numseqs;j++)
        {
                if(data[j].length+data[j].offset > maxlen)
                        maxlen = data[j].length+data[j].offset;
                if(data[j].offset < minoffset)
                        minoffset = data[j].offset;
        }

        printf("length:%d\n",maxlen);
        printf("offset:%d\n",minoffset);
        printf("start:\n");
        for(j=0;j<maxlen;j++)
        {
                int a=0,c=0,g=0,u=0;

                for(k=0;k<numseqs;k++)
                        if(data[k].length+data[k].offset > j)
                        {
                                if(j>data[k].offset)
                                        ch=data[k].nuc[j-data[k].offset] | 32;
                                else
                                        ch = '-';

                                if(ch=='a')a++;
                                if(ch=='c')c++;
                                if(ch=='g')g++;
                                if(ch=='u')u++;
                                if(ch=='t')u++;
                        }

                score=MAX(a,c);
                score=MAX(score,g);
                score=MAX(score,u);
                if(a+c+g+u)
                {
                        if(rev)
                                score=(score*6/(a+c+g+u)+8);
                        else
                                score=((8-score*6/(a+c+g+u))+8);
                }
                else
                        score=8;
                printf("%d\n",score);
        }
        exit(0);
}