Square root filtration values for alpha and delaunay-cech complex #1138
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…nay cech. Python hints for delaunay complex family
| // For users to be able to define their own sqrt function on their desired Filtration_value type | ||
| using std::sqrt; |
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You could also put it next to the single place where it is used, but it is ok here.
| std::clog << "Alpha complex can be, or not, weighted (requires a file containing weights values).\n\n"; | ||
| std::clog << "Weighted Alpha complex can have negative filtration values. If '-square-root-filtrations' is"; |
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Should we mention something like that in the documentation of Alpha_complex as well?
| if constexpr (square_root_filtrations) | ||
| filt = sqrt(filt); | ||
| complex.assign_filtration(sh, max(filt, Filtration_value(0))); |
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I think it would be safer to do the max with 0 before the sqrt.
| filt = sqrt(filt); | ||
| // maxf = filt except for rounding errors | ||
| maxf = max(maxf, filt); |
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I think there is a slight risk that a rounding error can make filt negative, with unpredictable results. It feels silly to use sqrt(max(filt,0)), but I don't know if there is an easy way to avoid it. Well, maybe replacing max(maxf,filt) by a hand-written comparison so we know what happens when filt is NaN, but it feels like a gratuitous use of NaN.
| :param precision: Delaunay complex precision can be 'fast', 'safe' or 'exact'. Default is 'safe'. | ||
| :type precision: string | ||
| Args: | ||
| points (Iterable[Iterable[float]]): A list of points in d-Dimension. |
| @@ -354,8 +355,10 @@ class Alpha_complex { | |||
| * It also computes the filtration values accordingly to the \ref createcomplexalgorithm if default_filtration_value | |||
| * is not set. | |||
| * | |||
| * \tparam square_root_filtrations If false (default value), it assigns to each simplex a filtration value equal to | |||
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(ignore the exact names I use here)
I wonder what is more natural between do_sqrt=true/false and output_squared_values=true/false. As the person writing the code, it is natural to ask if you should call sqrt. As the user... I am not sure, it might be the other one.
Fix #80 and #771