I've run your python code for chapter3 and its generating an error for both the python and r code.

The python generates

NameError: name 'unique' is not defined

Whereas r code generates an error code because there doesn't seem to be any function called spine.chart.
I've tried the UK finger charts and they are close but where did you find the spine.chart() function as it doesn't show up anywhere on google, GitHub, cran or rdocumentation websites. Was that a custom function?

Error in spine.chart(conjoint.results) (DA420_Project3a.R#147): could not find function "spine.chart"
Show stack trace

When I go to load the program for chapter six there are whole chunks of code that are needed duplicates, weird formatting \ and it asks for attribute ix which doesn't exist in the data.

Why are these elements in the textbook code?

Hi, I am reading your book and try to replicate your results. In the R code for Chapter_3, there's a R code file called "R_utility_program_1.R". In its line 254 and 419, the function effect.name.map() are called. However, this function doesn't exist. I just drop this function and the code works fine. Would this function be a mistake?