NEWS.md

In spdesign: Designing Stated Preference Experiments

spdesign v0.0.5

• Removed a check for all levels existing in the supplied candidate set. This caused errors when using restrictions on attribute level occurrence and a supplied candidate set.
• Added a check to the modified federov algorithm to ensure that the new candidate row from the candidate set does not already exist in the design candidate.
• Minor bug fixes

spdesign v0.0.4

• Added function level_balance() that produces a list of level occurrences in the design to inspect level balance
• Updates to documentation, examples, and syntax description
• Minor bug fixes

spdesign v0.0.3

• Fixed a bug related to optimizing for c-efficiency where it would sometimes fail to correctly identify the denominator.
• Fixed several bugs related to using a supplied candidate set with alternative specific constants and attributes. Checks have been updated. The code will now also add zero-columns for alternative specific constants and attributes in the utility functions where they are not present. This ensures that all matrices used when calculating the first- and second-order derivatives of the utility functions are square.
• Fixed an issue where it failed to catch a mismatch in naming between the supplied candidate set and the utilty functions which caused hard to debug situations. Error messages should now catch this and provide additional information to help find the cause. Syntax is updated to reflect this as well.
• Fixed an issue where the full factorial would be generated even when the "rsc" algorithm was used, which caused memory issues for large designs. It is now only generated for the "random" and "federov" algorithms. A small section is added to the syntax vignette to clarify this.
• Minor bug fixes

spdesign v0.0.2

• New function ´probabilities()´ will now return the choice probabilities by choice task.
• Suppress warnings when calculating the correlation between the blocking column and the attributes to avoid warning when calculating correlation with respect to a constant.
• After a number of candidates without improvement try a new design candidate when using the RSC algorithm
• Updated package load message
• Fixed roxygen @docType issue

spdesign v0.0.1

• This is the first working version of the spdesign package that is able to create simple efficient designs for the MNL model.

spdesign documentation built on Oct. 18, 2024, 5:07 p.m.