tercen / anova2_pg

Analysis Of Variance: A statistical model to analyze the differences among Means in a sample. Often used to test a Null Hypothesis in experimental data. Calculation uses two independent variables.

ANOVA 2-way operator

Description

The anova2 operator tests for a significant difference in the mean between any of the groups in the input data.

Usage

Input projection	.
y-axis	measurement value
colors	represents the groups to compare

Input parameters	.
Grouping Variable 1	Treat the ANOVA grouping variable 1 as categorical (dft) or numerical.
Grouping Variable 2	Treat the ANOVA grouping variable 2 as categorical (dft) or numerical.
Include Interaction	Fit ANOVA model using a factor1:factor2 interaction term (dft = "No").

Output relations	.
pFactor1	p-value for the probability that all group means for Factor1 are equal (groupingType = categorical) or the slope of the straight line fit is equal to zero (groupingType = continuous), accounting for Factor2. Hence, a low value indicates a significant effect for Factor1.
pFactor2	p-value for the probability that all group means for Factor2 are equal (groupingType = categorical) or the slope of the straight line fit is equal to zero (groupingType = continuous), accounting for Factor1. Hence, a low value indicates a significant effect for Factor2.
pFactor3	p-value for the interaction between Factor1 and Factor2 (if required). A low value for pFactor3 indicates an effect of Factor2 that is different in the groups of Factor1 (or vice versa).
logpFactor1-3	the significance of pFactors 1-3, respectively, as -10 log(pFactor).

Details

2-way ANOVA is used for data with two grouping factors, but with more than 2 groups. It test for a significant difference in the mean between any of the groups. As such, it is a generalization of the two sample t-test that works for two groups only. The operator is based on the anova R function.

The grouping factors must be added as data colors. The grouping can be by categorical and/or continuous variables. In the latter case a straight line regression is performed. There is an option to add an interaction term to the ANOVA model.

References

See Analysis of variance on Wikipedia.

See Also

anova1

anova2_pg's Issues

ANOVA Two Factor

Planning

delta output

Delta output variable cannot be defined unambigeously for ANOVA, remove!

numeric

Please use the term "numeric" throughout, instead of "contineous"