Maintainer: ‘Yifu Yan <yanyifu94@hotmail.com>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: person(given = "Yifu",
                    family = "Yan",
                    role = c("aut", "cre"),
                    email = "yanyifu94@hotmail.com")
as necessary.
Problems with news in ‘NEWS.md’:
No news entries found.
Maintainer: ‘Yifu Yan <yanyifu94@hotmail.com>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: person(given = "Yifu",
                    family = "Yan",
                    role = c("aut", "cre"),
                    email = "yanyifu94@hotmail.com")
as necessary.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
Namespace in Imports field not imported from: ‘lubridate’
  All declared Imports should be used.
Problems with news in ‘NEWS.md’:
No news entries found.
Namespace in Imports field not imported from: ‘lubridate’
  All declared Imports should be used.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in 'NEWS.md':
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
Problems with news in 'NEWS.md':
No news entries found.
Problems with news in ‘NEWS.md’:
No news entries found.
'LazyData' is specified without a 'data' directory
Problems with news in ‘NEWS.md’:
No news entries found.
'LazyData' is specified without a 'data' directory
Problems with news in 'NEWS.md':
No news entries found.
'LazyData' is specified without a 'data' directory