The summary method of
the output of x_from_power()
.
Arguments
- object
An
x_from_power
-class object, such as the output ofx_from_power()
, or an object of the classn_region_from_power
, such as the output ofn_region_from_power()
.- ...
Additional arguments. Not used for now.
- x
The output of
summary.x_from_power()
, thesummary
method of anx_from_power
object, which is the output ofx_from_power()
, or the output ofsummary.n_region_from_power()
, thesummary
method of ann_region_from_power
object (the output ofn_region_from_power()
).- digits
The number of digits after the decimal when printing the results.
Value
The summary
method for
x_from_power
objects returns an
object of the class
summary.x_from_power
, which is
simply the output of x_from_power()
,
with a print
method dedicated for
detailed summary. Please refer
to x_from_power()
for the contents.
The print
-method of summary.x_from_power
objects returns the object x
invisibly.
It is called for its side effect.
The print
-method of summary.n_region_from_power
objects returns the object x
invisibly.
It is called for its side effect.
Details
The summary
method simply prepares the
results of x_from_power()
to be printed in details.
Examples
# Specify the population model
mod <-
"
m ~ x
y ~ m + x
"
# Specify the population values
mod_es <-
"
m ~ x: m
y ~ m: l
y ~ x: n
"
# Generate the datasets
sim_only <- power4test(nrep = 5,
model = mod,
pop_es = mod_es,
n = 100,
do_the_test = FALSE,
iseed = 2345)
#> Simulate the data:
#> Fit the model(s):
# Do a test
test_out <- power4test(object = sim_only,
test_fun = test_parameters,
test_args = list(pars = "m~x"))
#> Do the test: test_parameters: CIs (pars: m~x)
# Determine the sample size with a power of .80 (default)
power_vs_n <- x_from_power(test_out,
x = "n",
progress = TRUE,
target_power = .80,
final_nrep = 5,
max_trials = 1,
seed = 1234)
#>
#> --- Setting ---
#>
#> Algorithm: bisection
#> Goal: ci_hit
#> What: point (Estimated Power)
#>
#> --- Progress ---
#>
#> - Set 'progress = FALSE' to suppress displaying the progress.
#> - Set 'simulation progress = FALSE' to suppress displaying the progress
#> in the simulation.
#>
#> Initial interval: [100, 125]
#>
#>
#> Do the simulation for the upper bound:
#>
#> Try x = 125
#>
#> Updating the simulation for sample size: 125
#> Re-simulate the data:
#> Fit the model(s):
#> Update the test(s):
#> Update test_parameters: CIs (pars: m~x) :
#>
#> Estimated power at n: 1.000, 95.0% confidence interval: [1.000,1.000]
#>
#> Initial interval: [100, 125]
#>
#> - Rejection Rates:
#> [test]: test_parameters: CIs (pars: m~x)
#> [test_label]: m~x
#> n est p.v reject r.cilo r.cihi
#> 1 100 0.298 1.000 0.800 0.449 1.151
#> 2 125 0.310 1.000 1.000 1.000 1.000
#>
#> One of the bounds in the interval is already a solution.
#>
#> - 'nls()' estimation skipped when less than 4 values of predictor examined.
#> Solution found.
#>
#>
#> --- Final Stage ---
#>
#> - Start at 2025-09-05 00:16:33
#> - Rejection Rates:
#>
#> [test]: test_parameters: CIs (pars: m~x)
#> [test_label]: m~x
#> n est p.v reject r.cilo r.cihi
#> 1 100 0.298 1.000 0.800 0.449 1.151
#> 2 125 0.310 1.000 1.000 1.000 1.000
#> Notes:
#> - n: The sample size in a trial.
#> - p.v: The proportion of valid replications.
#> - est: The mean of the estimates in a test across replications.
#> - reject: The proportion of 'significant' replications, that is, the
#> rejection rate. If the null hypothesis is true, this is the Type I
#> error rate. If the null hypothesis is false, this is the power.
#> - r.cilo,r.cihi: The confidence interval of the rejection rate, based
#> on normal approximation.
#> - Refer to the tests for the meanings of other columns.
#>
#> - Estimated Power Curve:
#>
#> Call:
#> power_curve(object = by_x_1, formula = power_model, start = power_curve_start,
#> lower_bound = lower_bound, upper_bound = upper_bound, nls_args = nls_args,
#> nls_control = nls_control, verbose = progress)
#>
#> Predictor: n (Sample Size)
#>
#> Model:
#>
#> Call: stats::glm(formula = reject ~ x, family = "binomial", data = reject1)
#>
#> Coefficients:
#> (Intercept) x
#> -75.3328 0.7672
#>
#> Degrees of Freedom: 9 Total (i.e. Null); 8 Residual
#> Null Deviance: 6.502
#> Residual Deviance: 5.004 AIC: 9.004
#>
#>
#> - Final Value: 100
#>
#> - Final Estimated Power: 0.8000
#> - Confidence Interval: [0.4494; 1.1506]
#> - CI Level: 95.00%
summary(power_vs_n)
#>
#> ====== x_from_power Results ======
#>
#> Call:
#> x_from_power(object = test_out, x = "n", target_power = 0.8,
#> progress = TRUE, max_trials = 1, final_nrep = 5, seed = 1234)
#>
#> Predictor (x): Sample Size
#>
#> - Target Power: 0.800
#> - Goal: Find 'x' with the confidence interval of the estimated power
#> enclosing the target power.
#>
#> === Major Results ===
#>
#> - Final Value (Sample Size): 100
#>
#> - Final Estimated Power: 0.800
#> - Confidence Interval: [0.449; 1.151]
#> - Level of confidence: 95.0%
#> - Based on 5 replications.
#>
#> === Technical Information ===
#>
#> - Algorithm: bisection
#> - The range of values explored: 100 to 125
#> - Time spent in the search: 0.5368 secs
#> - The final crude model for the power-predictor relation:
#>
#> Model Type: Logistic Regression
#>
#> Call:
#> power_curve(object = by_x_1, formula = power_model, start = power_curve_start,
#> lower_bound = lower_bound, upper_bound = upper_bound, nls_args = nls_args,
#> nls_control = nls_control, verbose = progress)
#>
#> Predictor: n (Sample Size)
#>
#> Model:
#>
#> Call: stats::glm(formula = reject ~ x, family = "binomial", data = reject1)
#>
#> Coefficients:
#> (Intercept) x
#> -75.3328 0.7672
#>
#> Degrees of Freedom: 9 Total (i.e. Null); 8 Residual
#> Null Deviance: 6.502
#> Residual Deviance: 5.004 AIC: 9.004
#>
#> - Detailed Results:
#>
#> [test]: test_parameters: CIs (pars: m~x)
#> [test_label]: m~x
#> n est p.v reject r.cilo r.cihi
#> 1 100 0.298 1.000 0.800 0.449 1.151
#> 2 125 0.310 1.000 1.000 1.000 1.000
#> Notes:
#> - n: The sample size in a trial.
#> - p.v: The proportion of valid replications.
#> - est: The mean of the estimates in a test across replications.
#> - reject: The proportion of 'significant' replications, that is, the
#> rejection rate. If the null hypothesis is true, this is the Type I
#> error rate. If the null hypothesis is false, this is the power.
#> - r.cilo,r.cihi: The confidence interval of the rejection rate, based
#> on normal approximation.
#> - Refer to the tests for the meanings of other columns.
#>