Shell Programming and Scripting

awk ' /<data>/ {
        f = 1;
        print $0
        next;
} /<\/data>/ && s {
        f = 0;
        m = 0;
        k = 12;
        while(m < j)
        {
                for(i=1;i<=nf;i++)
                {
                        printf "%s\t", a[i,++m];
                        if(i >= 2)
                        {
                                b[i] = (a[i,k] * a[i,m]);
                                ++k;
                        }
                }
                a6 = b[2] - b[3] - b[4] - b[5];
                printf "%.4f", a6;
                a6 = 0;
                printf "\n"
                if(k > nf) k=12;
        }
        j = 0;
        print $0;
} f == 1 {
        for(i=1;i<=NF;i++)
        {
                a[i,++j] = $i;
        }
        if(a[1,11] == 6 )
                s = 1;
        if(a[1,11] != 6 )
                s = 0;
        nf = NF;
}' file

$ ./hayreter
<data>
21      0.00    0.00    0.57    0.57    -0.3876
21      0.00    0.00    -0.19   0.19    -0.0114
6       -0.63   0.12    0.31    0.37    0.1495
24      -0.44   0.15    0.25    0.30    0.0707
-13     -0.23   0.37    0.13    0.14    0.0084
</data>
<data>
1       0.00    0.00    0.10    0.10    -0.0590
-1      0.00    0.00    -0.66   0.66    -0.0330
6       -0.17   0.40    0.27    0.32    -0.3064
24      -0.48   -0.24   0.12    0.15    0.0972
-13     0.17    -0.44   0.33    0.18    0.0004
</data>

awk '/^[ \t]*<data>/{data=1;countrow=0;rec[countrow++]=$0;next}
/^[ \t]*<\/data>/{
 if(output) {
  print rec[0]
  n=split(rec[foundat],pattline)
  for(i=1;i<countrow;i++) {
   split(rec[i],otherline)
   c=0
   for(j=2;j<=n;j++) {
    if(j==2) {c=pattline[j]*otherline[j];continue}
    c-=(pattline[j]*otherline[j])
   }
   print rec[i],c
  }
  print
 } 
 else
  for(i in rec) delete rec[i]
 output=foundat=data=0;next
}
data{
 if(!output && $1=="6") { output=1; foundat=countrow }
 rec[countrow++]=$0
}' file

awk ' /<data>/ {                                                # Search for pattern: <data>
        f = 1;                                                  # If found set f = 1
        print $0                                                # Print <data> tag
        next;                                                   # Stop processing current record
} /<\/data>/ && s {                                             # Search for pattern: </data>
        f = 0;                                                  # If found set f = 0
        m = 0;                                                  # m = 0  (counter for fetching all array elements)
        k = 12;                                                 # k = 12 (index of 2nd element in row c)
        while(m < j)                                            # While m < j
        {
                for(i=1;i<=nf;i++)                              # For each records in 2D array
                {
                        printf "%s\t", a[i,++m];                # Print records
                        if(i >= 2)                              # If array index i > 2 (starting from second element)
                        {
                                b[i] = (a[i,k] * a[i,m]);       # Multiply current record with row c record.
                                ++k;
                        }
                }
                a6 = b[2] - b[3] - b[4] - b[5];                 # Subtract elements in array b and assign to a6
                printf "%.4f", a6;                              # Print a6
                a6 = 0;                                         # Reinitialize a6 = 0
                printf "\n"
                if(k > nf) k=12;                                # if k index goes beyond number of recs, reset to 12
        }
        j = 0;
        print $0;                                               # Print </data> tag
} f == 1 {                                                      # If f == 1
        for(i=1;i<=NF;i++)                                      # Creating a 2D array with elements in <data> tag.
        {
                a[i,++j] = $i;
        }
        if(a[1,11] == 6 )                                       # If row c first element == 6
                s = 1;                                          # Set s = 1
        if(a[1,11] != 6 )                                       # If row c first element != 6
                s = 0;                                          # Set s = 0
        nf = NF;                                                # Set nf = number of records in line NF
}' file

1   (1,1)       0.00  (2,2)     0.00  (3,3)     0.10  (4,4)     0.10 (5,5)
-1  (1,6)       0.00  (2,7)     0.00  (3,8)     -0.66 (4,9)     0.66 (5,10)
6   (1,11)      -0.17 (2,12)    0.40  (3,13)    0.27  (4,14)    0.32 (5,15)
24  (1,16)      -0.48 (2,17)    -0.24 (3,18)    0.12  (4,19)    0.15 (5,20)
-13 (1,21)      0.17  (2,22)    -0.44 (3,23)    0.33  (4,24)    0.18 (5,25)