The EnvStats functions listed below are useful for power and sample size calculations.
Confidence Intervals
Function Name | Description |
ciTableProp | Confidence intervals for binomial proportion, or |
difference between two proportions, following Bacchetti (2010) | |
ciBinomHalfWidth | Compute the half-width of a confidence interval for a |
Binomial proportion or the difference between two proportions. | |
ciBinomN | Compute the sample size necessary to achieve a specified |
half-width of a confidence interval for a Binomial proportion or | |
the difference between two proportions. | |
plotCiBinomDesign | Create plots for a sampling design based on a confidence interval |
for a Binomial proportion or the difference between two proportions. | |
ciTableMean | Confidence intervals for mean of normal distribution, or |
difference between two means, following Bacchetti (2010) | |
ciNormHalfWidth | Compute the half-width of a confidence interval for the mean of a |
Normal distribution or the difference between two means. | |
ciNormN | Compute the sample size necessary to achieve a specified half-width |
of a confidence interval for the mean of a Normal distribution or | |
the difference between two means. | |
plotCiNormDesign | Create plots for a sampling design based on a confidence interval |
for the mean of a Normal distribution or the difference between | |
two means. | |
ciNparConfLevel | Compute the confidence level associated with a nonparametric |
confidence interval for a percentile. | |
ciNparN | Compute the sample size necessary to achieve a specified |
confidence level for a nonparametric confidence interval for | |
a percentile. | |
plotCiNparDesign | Create plots for a sampling design based on a nonparametric |
confidence interval for a percentile. |
Hypothesis Tests
Function Name | Description |
aovN | Compute the sample sizes necessary to achieve a |
specified power for a one-way fixed-effects analysis | |
of variance test. | |
aovPower | Compute the power of a one-way fixed-effects analysis of |
variance test. | |
plotAovDesign | Create plots for a sampling design based on a one-way |
analysis of variance. | |
propTestN | Compute the sample size necessary to achieve a specified |
power for a one- or two-sample proportion test. | |
propTestPower | Compute the power of a one- or two-sample proportion test. |
propTestMdd | Compute the minimal detectable difference associated with |
a one- or two-sample proportion test. | |
plotPropTestDesign | Create plots involving sample size, power, difference, and |
significance level for a one- or two-sample proportion test. | |
tTestAlpha | Compute the Type I Error associated with specified values for |
for power, sample size(s), and scaled MDD for a one- or | |
two-sample t-test. | |
tTestN | Compute the sample size necessary to achieve a specified |
power for a one- or two-sample t-test. | |
tTestPower | Compute the power of a one- or two-sample t-test. |
tTestScaledMdd | Compute the scaled minimal detectable difference |
associated with a one- or two-sample t-test. | |
plotTTestDesign | Create plots for a sampling design based on a one- or |
two-sample t-test. | |
tTestLnormAltN | Compute the sample size necessary to achieve a specified |
power for a one- or two-sample t-test, assuming lognormal | |
data. | |
tTestLnormAltPower | Compute the power of a one- or two-sample t-test, assuming |
lognormal data. | |
tTestLnormAltRatioOfMeans | Compute the minimal or maximal detectable ratio of means |
associated with a one- or two-sample t-test, assuming | |
lognormal data. | |
plotTTestLnormAltDesign | Create plots for a sampling design based on a one- or |
two-sample t-test, assuming lognormal data. | |
linearTrendTestN | Compute the sample size necessary to achieve a specified |
power for a t-test for linear trend. | |
linearTrendTestPower | Compute the power of a t-test for linear trend. |
linearTrendTestScaledMds | Compute the scaled minimal detectable slope for a t-test |
for linear trend. | |
plotLinearTrendTestDesign | Create plots for a sampling design based on a t-test for |
linear trend. |
Prediction Intervals
Normal Distribution Prediction Intervals
Function Name | Description |
predIntNormHalfWidth | Compute the half-width of a prediction |
interval for a normal distribution. | |
predIntNormK | Compute the required value of \(K\) for |
a prediction interval for a Normal | |
distribution. | |
predIntNormN | Compute the sample size necessary to |
achieve a specified half-width for a | |
prediction interval for a Normal | |
distribution. | |
plotPredIntNormDesign | Create plots for a sampling design |
based on the width of a prediction | |
interval for a Normal distribution. | |
predIntNormTestPower | Compute the probability that at least |
one future observation (or mean) | |
falls outside a prediction interval | |
for a Normal distribution. | |
plotPredIntNormTestPowerCurve | Create plots for a sampling |
design based on a prediction interval | |
for a Normal distribution. | |
predIntNormSimultaneousTestPower | Compute the probability that at |
least one set of future observations | |
(or means) violates the given rule | |
based on a simultaneous prediction | |
interval for a Normal distribution. | |
plotPredIntNormSimultaneousTestPowerCurve | Create plots for a sampling design |
based on a simultaneous prediction | |
interval for a Normal distribution. |
Lognormal Distribution Prediction Intervals
Function Name | Description |
predIntLnormAltTestPower | Compute the probability that at least |
one future observation (or geometric | |
mean) falls outside a prediction | |
interval for a lognormal distribution. | |
plotPredIntLnormAltTestPowerCurve | Create plots for a sampling design |
based on a prediction interval for a | |
lognormal distribution. | |
predIntLnormAltSimultaneousTestPower | Compute the probability that at least |
one set of future observations (or | |
geometric means) violates the given | |
rule based on a simultaneous | |
prediction interval for a lognormal | |
distribution. | |
plotPredIntLnormAltSimultaneousTestPowerCurve | Create plots for a sampling design |
based on a simultaneous prediction | |
interval for a lognormal distribution. |
Nonparametric Prediction Intervals
Function Name | Description |
predIntNparConfLevel | Compute the confidence level associated with |
a nonparametric prediction interval. | |
predIntNparN | Compute the required sample size to achieve |
a specified confidence level for a | |
nonparametric prediction interval. | |
plotPredIntNparDesign | Create plots for a sampling design based on |
the confidence level and sample size of a | |
nonparametric prediction interval. | |
predIntNparSimultaneousConfLevel | Compute the confidence level associated with |
a simultaneous nonparametric prediction | |
interval. | |
predIntNparSimultaneousN | Compute the required sample size for a |
simultaneous nonparametric prediction | |
interval. | |
plotPredIntNparSimultaneousDesign | Create plots for a sampling design based on |
a simultaneous nonparametric prediction | |
interval. | |
predIntNparSimultaneousTestPower | Compute the probability that at least one |
set of future observations violates the | |
given rule based on a nonparametric | |
simultaneous prediction interval. | |
plotPredIntNparSimultaneousTestPowerCurve | Create plots for a sampling design based on |
a simultaneous nonparametric prediction | |
interval. |
Tolerance Intervals
Function Name | Description |
tolIntNormHalfWidth | Compute the half-width of a tolerance |
interval for a normal distribution. | |
tolIntNormK | Compute the required value of \(K\) for a |
tolerance interval for a Normal distribution. | |
tolIntNormN | Compute the sample size necessary to achieve a |
specified half-width for a tolerance interval | |
for a Normal distribution. | |
plotTolIntNormDesign | Create plots for a sampling design based on a |
tolerance interval for a Normal distribution. | |
tolIntNparConfLevel | Compute the confidence level associated with a |
nonparametric tolerance interval for a specified | |
sample size and coverage. | |
tolIntNparCoverage | Compute the coverage associated with a |
nonparametric tolerance interval for a specified | |
sample size and confidence level. | |
tolIntNparN | Compute the sample size required for a nonparametric |
tolerance interval with a specified coverage and | |
confidence level. | |
plotTolIntNparDesign | Create plots for a sampling design based on a |
nonparametric tolerance interval. |