slope_rast

only for yearly rast

library(rtrend)
library(terra)
#> terra 1.7.83

f = system.file("rast/MOD15A2_LAI_China_G050_2001-2020.tif", package = "rtrend")
r = rast(f)
r
#> class       : SpatRaster 
#> dimensions  : 80, 140, 20  (nrow, ncol, nlyr)
#> resolution  : 0.5, 0.5  (x, y)
#> extent      : 70, 140, 15, 55  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (EPSG:4326) 
#> source      : MOD15A2_LAI_China_G050_2001-2020.tif 
#> names       :      LAI,      LAI,      LAI,     LAI,      LAI,      LAI, ... 
#> min values  : 0.000000, 0.000000, 0.000000, 0.00000, 0.000000, 0.000000, ... 
#> max values  : 5.692542, 5.479348, 5.585326, 5.33587, 5.822826, 5.533152, ... 
#> time (days) : 2001-01-01 to 2020-01-01
time(r)
#>  [1] "2001-01-01" "2002-01-01" "2003-01-01" "2004-01-01" "2005-01-01"
#>  [6] "2006-01-01" "2007-01-01" "2008-01-01" "2009-01-01" "2010-01-01"
#> [11] "2011-01-01" "2012-01-01" "2013-01-01" "2014-01-01" "2015-01-01"
#> [16] "2016-01-01" "2017-01-01" "2018-01-01" "2019-01-01" "2020-01-01"

slp <- slope_rast(r, period = c(2001, 2020),
  outfile = "LAI_trend.tif", overwrite = TRUE,
  fun = rtrend::slope_mk, .progress = "none"
)
slp
#> class       : SpatRaster 
#> dimensions  : 80, 140, 2  (nrow, ncol, nlyr)
#> resolution  : 0.5, 0.5  (x, y)
#> extent      : 70, 140, 15, 55  (xmin, xmax, ymin, ymax)
#> coord. ref. : lon/lat WGS 84 (EPSG:4326) 
#> source(s)   : memory
#> names       :       slope, pvalue 
#> min values  : -0.01830315,      0 
#> max values  :  0.04475858,      1
plot(slp)

#> [1] TRUE