T-Test — pamlttest • pamlj

Power analysis for one-sample, paired, and independent-samples t-tests: estimate required sample size, power, or minimum detectable effect size.

pamlttest(
  aim = "n",
  mode = "ttestind",
  ttestind_es = 0.5,
  ttestind_n = 20,
  ttestind_nratio = 1,
  ttestpaired_es = 0.5,
  ttestpaired_n = 20,
  ttestone_es = 0.5,
  ttestone_n = 20,
  is_equi = FALSE,
  equi_limit = 0.1,
  power = 0.9,
  sig.level = 0.05,
  alternative = "two.sided",
  plot_contour = FALSE,
  plot_escurve = FALSE,
  plot_ncurve = FALSE,
  plot_log = TRUE,
  plot_palette = "viridis",
  plot_x = "none",
  plot_y = "none",
  plot_custom_labels = FALSE,
  plot_z = "none",
  plot_x_from = 0,
  plot_x_to = 0,
  plot_z_lines = 0,
  plot_z_value = list(),
  plot_to_table = FALSE,
  explain = FALSE,
  .caller = "ttest",
  .interface = "jamovi",
  ttestind_ttest = "-",
  ttestind_ngroup = 0,
  ttestind_d = 0,
  ttestind_useit = FALSE,
  ttestpaired_ttest = "-",
  ttestpaired_obsn = 0,
  ttestpaired_d = 0,
  ttestpaired_useit = FALSE,
  ttestpaired_dind = "-",
  ttestpaired_r = 0,
  ttestpaired_dz = 0,
  ttestpaired_d_useit = FALSE,
  ttestone_ttest = "-",
  ttestone_obsn = 0,
  ttestone_d = 0,
  ttestone_useit = FALSE
)

Arguments

aim: The aim of the analysis: n for required N, power for estimated power and es for minimal detectable effect size
mode: .
ttestind_es: Expected Cohe's d
ttestind_n: Sample size per group
ttestind_nratio: Relative size of the two groups. 1 means group of equal size, ratio>1 means that one group is ratio times larger than the other.
ttestpaired_es: Expected Cohe's d_z, defined as the mean difference divided by the standard deviation of the difference score
ttestpaired_n: Expected sample size (number of paires)
ttestone_es: Expected Cohe's d
ttestone_n: Expected sample size
is_equi: When TRUE, perform an equivalence test to show that a true effect is small enough to be considered practically negligible
equi_limit: .
power: Minimal desired power (1-Beta)
sig.level: Critical alpha (significance level to be used in the analysis)
alternative: Wheather the test is two-tailed (two.sided) or one-tailed (greater).
plot_contour: .
plot_escurve: .
plot_ncurve: .
plot_log: .
plot_palette: .
plot_x: .
plot_y: .
plot_custom_labels: .
plot_z: .
plot_x_from: .
plot_x_to: .
plot_z_lines: .
plot_z_value: .
plot_to_table: .
explain: not used in R
.caller: .
.interface: .
ttestind_ttest: not used in R
ttestind_ngroup: not used in R
ttestind_d: not used in R
ttestind_useit: not used in R
ttestpaired_ttest: not used in R
ttestpaired_obsn: not used in R
ttestpaired_d: not used in R
ttestpaired_useit: not used in R
ttestpaired_dind: not used in R
ttestpaired_r: not used in R
ttestpaired_dz: not used in R
ttestpaired_d_useit: not used in R
ttestone_ttest: not used in R
ttestone_obsn: not used in R
ttestone_d: not used in R
ttestone_useit: not used in R

Value

A results object containing:

`results$intro`					a html
`results$issues`					a html
`results$extrainfo`					a html
`results$powertab`					a table
`results$powerbyes`					a table
`results$plotnotes`					a html
`results$powerContour`					an image
`results$powerEscurve`					an image
`results$powerNcurve`					an image
`results$powerCustom`					an image
`results$customnotes`					a html
`results$customtable`					a table

Tables can be converted to data frames with asDF or as.data.frame. For example:

results$powertab$asDF

as.data.frame(results$powertab)