make_strata: Make and assign strata based on two input columns

In jstrunk001/RForInvt: Forest Inventory Data Compilation and FVS Growth Projections

Make and assign strata based on two input columns

Description

Make and assign strata based on two input attributes and some parameters functions are make_strata and assign_strata

Usage

make_strata(
  data,
  x1 = "PlotStrata1",
  x2 = "Elev.P95",
  split_x1 = c("qt", "eq"),
  split_x2 = c("qt", "eq"),
  nest_x2 = T,
  n1 = 10,
  n2 = 10,
  type_x1 = c("factor", "numeric")[1],
  type_x2 = c("numeric", "factor")[1],
  min_recs = 7,
  precision = 0,
  collapse = T
)

Arguments

data	input data
x1	name of input x field
x2	name of input y field
split_x1	how to split - equal interval or quantile based
split_x2	how to split - equal interval or quantile based
nest_x2	should x2 be nested in x1, or should x1 and x2 be split independently
n1	number of strata for x1
n2	number of strata for x2
type_x1	is x1 numeric or factor
type_x2	is x2 numeric or factor
min_recs	what is the minimum number of records in a stratum before collapse
precision	what precision is retained for cutting numeric values into strata

Details

<Delete and Replace>

Revision History

1.0	2019 01 24 created
1.1	2020 06 25 updated to allow more complex inputs

Value

make_strata returns a data.frame of strata boundaries assign_strata takes a data.frame and appends a column with the stratum name for each record

Author(s)

Jacob Strunk <[e-mail]>

Examples

      #prepare pseudo data
      n=500
      hts = sample(1:150,n,T)
      dbhs = abs(hts/5 + rnorm(#' )*2)
      dat_test = data.frame(height = hts , dbh = dbhs, height_cat = cut(hts,10) , dbh_cat = cut(dbhs,10))
      plot(dbhs,hts)

      #example 1 factor and numeric
      str_test = make_strata(
        dat_test
        , x1="height_cat"
        , x2="dbh"
        , split_x1 =c("qt","eq")[1]
        , split_x2 =c("qt","eq")[1]
        , nest_x2 =  T
        , n1 = 10
        , n2 = 10
        , type_x1 = "factor"
        , type_x2 = "numeric"
        , min_recs = 7
        , precision = 0
      )


      res = assign_strata(
       str_test
        ,dat_test
      )

      res$stratum

      summary(lm(height ~ dbh , data = res))
      summary(lm(height ~ dbh_cat , data = res))
      summary(lm(height ~ stratum , data = res))

      #example 2 numeric and numeric
      str_test1 = make_strata(
        dat_test
        , x1="height"
        , x2="dbh"
        , split_x1 =c("qt","eq")[1]
        , split_x2 =c("qt","eq")[1]
        , nest_x2 =  T
        , n1 = 10
        , n2 = 10
        , type_x1 = "numeric"
        , type_x2 = "numeric"
        , min_recs = 7
        , precision = 0
      )

      res1 = assign_strata(
        str_test1
        ,dat_test
      )

      #example 3 numeric and factor
      str_test2 = make_strata(
        dat_test
        , x1="height"
        , x2="dbh_cat"
        , split_x1 =c("qt","eq")[1]
        , split_x2 =c("qt","eq")[1]
        , nest_x2 =  T
        , n1 = 10
        , n2 = 10
        , type_x1 = "numeric"
        , type_x2 = "factor"
        , min_recs = 7
        , precision = 0
      )

      res2 = assign_strata(
        str_test2
        ,dat_test
      )

jstrunk001/RForInvt documentation built on April 17, 2025, 5:02 p.m.