revisit_rand: Create a revisit design with random assignment to panels and...

In USEPA/spsurvey: Spatial Sampling Design and Analysis

Create a revisit design with random assignment to panels and time periods

Description

Create a revisit design for a survey that specifies the panels and time periods that will be sampled by random selection of panels and time periods. Three options for random assignments are "period" where the number of time periods to be sampled in a panel is fixed, "panel" where the number panels to be sampled in a time period is fixed, and "none" where the number of panel-period combinations is fixed.

Usage

revisit_rand(
  n_period,
  n_pnl,
  rand_control = "period",
  n_visit,
  nsamp,
  panel_name = "Random",
  begin = 1,
  skip = 1
)

Arguments

n_period	Number of time periods for the survey design. Typically, number of periods if sampling occurs once per period or number of months if sampling occurs once per month. (v, number of varieties (or treatments) in BIBD terms)
n_pnl	Number of panels
rand_control	Character value must be "none", "panel", or "period". Specifies whether the number of sample events will be fixed for each panel ("panel"), for each sample occasion ("occasion"), or for total panel-period combinations ("none"). Default is "panel".
n_visit	If rand_control is "panel", this is the number of panels that will be sampled in each time period. If rand_control is "period", this is the number of time periods to be sampled in each panel. If rand_control is "none", this is the total number of panel-period combinations that will have units sampled in the revisit design.
nsamp	Number of samples in each panel.
panel_name	Prefix for name of each panel
begin	Numeric name of first sampling occasion, e.g. a specific period.
skip	Number of sampling occasions to skip between planned sampling periods, e.g., sampling will occur only every 5 periods if skip = 5.

Details

The revisit design for a survey is created by random selection of panels and time periods that will have sample events. The number of sample occasions that will be visited by a panel is random.

Value

A two-dimensional array of sample sizes to be sampled for each panel and each time period.

Author(s)

Tony Olsen [e-mail]

See Also

revisit_bibd

create a balanced incomplete block panel revisit design

revisit_dsgn

create a panel revisit design

pd_summary

to summarize characteristics of a panel revisit design

Examples

revisit_rand(
  n_period = 20, n_pnl = 10, rand_control = "none", n_visit = 50,
  nsamp = 20
)
revisit_rand(
  n_period = 20, n_pnl = 10, rand_control = "panel", n_visit = 5,
  nsamp = 10
)
revisit_rand(
  n_period = 20, n_pnl = 10, rand_control = "period",
  n_visit = 5, nsamp = 10
)

USEPA/spsurvey documentation built on Jan. 26, 2024, 4:18 p.m.