The regression results can then be interpreted in the context of the before-multiplying-out form of the model. In particular, the significance level of the t-ratio of the newly-created variable helps ...

Example 55.3: Regression with Quantitative and Qualitative Variables At times it is desirable to have independent variables in the model that are qualitative rather than quantitative. This is easily ...

For the variable Phase, which has four levels (CR1, CR2, CR3, and Relapse), we need three dummy variables. We provide a R function factor2ind() , which creates a matrix of indicator variables from ...