sim_calc: Conducted a study with a internal pilot study and normally...

Description Usage Arguments Value Author(s) See Also

Description

This is an auxiliary function of 'sim_sample_pow'. It is conducting a study with a internal pilot study and normally distributed data. The calculated value of the test statistic is compared directly with the corresponding quantile of the t-distribution.

Usage

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sim_calc(n1, N0, sd_ber, delta = 0, Delta, test = 1, alpha = 0.05, beta = 0.2,
         adj = F, rule = F, nbound = 500)

Arguments

n1

Number. Size of the internal pilot study.

N0

Number. Size of the originally planned sample size.

sd_ber

Number. Actual standard deviation in the data.

delta

Number. Expectation difference of two samples.
If you select a Test for superiority/ difference then select 'delta = 0'.
Only if you select a Test for non-inferiority you can select 'delta != 0'.
Attention: If you chose 'test = 1' and 'delta != 0', the test for non-inferiority will
automatically be applied.
If not specified, delta is set to 0.

Delta

Number. Relevant difference of expected values in the alternative hypothesis.

test

Number. What type of hypothesis test should be performed. One-sided (Superiority/
Non-Inferiority test) or two-sided (Test for difference).
One-sided (test = 1): Superiortity H0: mu_x - mu_y <= 0 vs. H1: mu_x - mu_y > 0
Non-Inferiority H0: mu_x - mu_y >= delta vs. H1: mu_x - mu_y < delta
Two-sided (test = 2): Difference H0: |mu_x - mu_y| = 0 vs. H1: |mu_x - mu_y| != 0
Attention: Choice of delta. (see delta)
If not specified, the one-Sided Test (Superiority/ Non-Inferiority Test) is used.

alpha

Number. Desired alpha-level of the test.
If not specified, alpha is set to 0.05.

beta

Number. Acceptable beta error of the test.
If not specified, beta is set to 0.2.

adj

Logical. Should the one-sample variance, calculated in the internal pilot study, be adjusted?

rule

Logical. Should the sample size adjustment rule be applied by Wittes and Brittain?

nbound

Number. Upper limit of the sample size.
Attention: Only if you choose nbound can a suitable standard deviation range for the plots
be calculated automatically.
If no nbound are defined then a standard deviation range must be chosen (see sd_ber).

Value

This function returns a value if the simulation study rejects (1) or can not reject (0) the
null hypothesis.

Author(s)

Csilla van Lunteren

See Also

test_h0


vanLunteren/plan_norm documentation built on May 20, 2019, 12:32 p.m.