I want make a Time Series.
The data that I want to graph were measured on the same days and the same months for 4 years.
I have already searched a lot and as I understand it, I have a problem setting the frequency (frequency= ?) function according to the months of each year. The variable it's ozone.
I know the function start (star= (2017,3) if I understand it. is well.
I don't know how to set the frequency every 3 months in different years, but in the same months. (2017 in MARZ, APR, MAY; 2018 in MARZ, APR, MAY; 2019 in MARZ, APR, MAY; 2020 in MARZ, APR, MAY).
Data starts -MAR-01 and ends MAY-31. So for all the years measured.
Thanks for help me.