1. 2021-12-21 Re: [R] Sum every n (4) observations by group r-help Rasmus Liland 2. 2021-12-20 Re: [R] Sum every n (4) observations by group r-help Leonard Mada via R 3. 2021-12-19 Re: [R] Sum every n (4) observations by group r-help Avi Gross via R-he 4. 2021-12-19 Re: [R] Sum every n (4) observations by group r-help Miluji Sb 5. 2021-12-19 Re: [R] Sum every n (4) observations by group r-help Peter Langfelder 6. 2021-12-19 [R] Sum every n (4) observations by group r-help Miluji Sb