data: a string (values between 0 and 255) that contains packed floating-point numbers
startDoubleIndex: the zero-based index from which on data should be unpacked (from data[8*startDoubleIndex+1+additionalCharOffset]). Can be omitted in which case 0 is used
doubleCount: the amount of doubles that should be unpacked. Can be omitted in which case 0 is used (which indicates that the maximum of doubles should be unpacked from the indicated startIndex)
additionalCharOffset: a char offset that will be added before reading the doubles. Can be omitted, in which case 0 is used.