CpG Islands (counts 'GC' dinucleotides in a DNA sequence)
y = btd_CpG(x)
String of single-letter codes specifying a DNA sequence
Number of 'GC' dinucleotides (decimal integer)
y = btd_CpG(x)
count of all dinucleotides for which a Cytosine
nucleotide occurs next to a Guanine nucleotide.
--> y = btd_CpG("ATCGATCGATCGTATATGCTAGCTA") y = 2.