This function calculates the decimal day of the year of the input vector of dates. The dates must be in MATLAB serial date format.
For example, for datestr(now), MATLAB produces: "18-Jan-2008 14:33:27". The output of this function, called "date2doy" yields-
There are two outputs, the decimal date (can be a vector), and the fraction of the year completed by that date. From the example above, the fraction of the year is: "0.0481"
This function is very fast, and is ideal for embedding in larger applications that call date2doy many times.