NEWS

SOAs 1.4-1

include fastSP and fastSP.K functions based on code from Tian and Xu 2023+, with substantial modifications to fastSP (eventually remove unnecessary helper functions and possibly also fastSP.K entirely)

modified Spattern calculations to use full factorial based coding instead of the power coding, because this is faster and also works for non-prime and non-prime-power s
bug fix to Spattern: For a few cases, an individual weight for a main effect column was too large with the old calculation method, e.g. for column 124 with s=5, the weight was 4 instead of 3, due to numeric glitches (ceiling(log(124+1, base=5)) is 4).
removed iterators and itertools from imports field of DESCRIPTION
excluded documentation of internal function levels.no, and added an error message for the unlikely event that someone attempts to call base::levels on an object of class no

implemented the stratification pattern that was proposed by Tian and Xu (2022) and whose implementation is described in Groemping (2022b) (important functions: Spattern and dim_wt_tab; important supporting function: contr.Power yields contrasts for factors with s^el levels)

modified function createAB and documentation in SOAs2plus_regular: the He, Cheng and Tang (2018) strength 2+ SOAs now have orthogonal columns more often, because the columns for matrix B are selected from all columns that are not used for A (instead of only the columns that were not eligible for A). Users who need the previous behavior for reproducing a design from earlier package versions can use the argument old.
sped up the selection of columns for matrix B in case orthogonal columns are requested (work directly with coefficient matrix instead of using function length3 from package DoE.base)
added an internal function createAB_fast for SOAs2plus_regular: this bypasses orthogonality requests in order to obtain a fast solution or to forsake orthogonality in the hope of improved space-filling (argument orth)

added functions guide_SOAs and guide_SOAs_from_OA for providing guidance about implemented SOA constructions
various improvements of documentation, and update of references
BcolsFromBcolllist: changed vertex attributes to FALSE and TRUE instead of 0 and 1, in order to avoid a warning from package igraph
Bug fix: function OSOAs_hadamard did not work for n=8
Bug fix: handling of s in SOAs2plus_regular had a bug (leading to failure for s=9, because 9 was treated as a prime). Now, SOAs2plus_regular, SOA2plus_regulart and createAB (file utilitiesCreate.R) all have the same requirements for s: primes up to 19, powers of 2 up to 32, powers of 3 up to 27 (presumably, the larger numbers do not really work well, but are in principle possible)