R DHI

Author: davidfrantz

rstats/ard/.gitkeep

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+# global header, e.g., for loading libraries
+# library(...)
+
+# dates:     vector with dates     of input data (class: Date)
+# sensors:   vector with sensors   of input data (class: character)
+# bandnames: vector with bandnames of input data (class: character)
+force_rstats_init <- function(dates, sensors, bandnames){
+
+    return(c("cumulative", "minimum", "variation"))
+}
+
+
+# inarray:   2D-array with dim = c(length(dates), length(bandnames))
+#            No-Data values are encoded as NA.  (class: Integer)
+# dates:     vector with dates     of input data (class: Date)
+# sensors:   vector with sensors   of input data (class: character)
+# bandnames: vector with bandnames of input data (class: character)
+# nproc:     number of CPUs the UDF may use. Always 1 for pixel functions (class: Integer)
+force_rstats_pixel <- function(inarray, dates, sensors, bandnames, nproc){
+
+  s <- sum(inarray[,1], na.rm = TRUE) / 1e2
+  m <- min(inarray[,1], na.rm = TRUE)
+  v <- sd(inarray[,1],  na.rm = TRUE) / mean(inarray[,1],  na.rm = TRUE) * 1e4
+
+  return(c(s, m, v))
+}

rstats/ts/.gitkeep

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+# Dynamic Habitat Indices
+
+©
+Copyright 2023, David Frantz
+
+## Run with
+
+- program: ``force-higher-level``
+- submodule: ``TSA``
+- UDF type: ``RSTATS_TYPE = PIXEL``
+- required parameters:
+  - ``INTERPOLATE = RBF`` with very large kernels
+  - ``DATE_RANGE``: set to one(!) full year
+- required R libraries: none
+
+## References
+
+- Radeloff, V. C., M. Dubinin, N. C. Coops, A. Allen, T. M. Brooks, M. Clayton, G. Costa, C. H. Graham, D. Helmers, A. R. Ives, D. Kolesov, A. M. Pidgeon, G. Rapacciuolo, E. Razenkova, N. Suttidate, B. E. Young, L. Zhu, and M. Hobi. (2019): **The Dynamic Habitat Indices (DHIs) from MODIS and global biodiversity**. *Remote Sensing of Environment, 222*, 204-214. [10.1016/j.rse.2018.12.009](https://doi.org/10.1016/j.rse.2018.12.009)
+- Hobi, M.L., Dubinin, M., Graham, C.H., Coops, N.C., Clayton, M.K., Pidgeon, A.M., & Radeloff, V.C. (2017): **A comparison of Dynamic Habitat Indices derived from different MODIS products as predictors of avian species richness.** *Remote Sensing of Environment, 195*, 142-152. [10.1016/j.rse.2017.04018](https://doi.org/10.1016/j.rse.2017.04018)