Rounding error fix on WeightedIndex::update_weights() #956
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WeightedIndex::update_weights() uses subtraction on old_w. Rounding errors, particularly on f32, may bring total_weight to below 0. This PR makes sure a negative total_weight results in an error. This replaces PR rust-random#955 which was invalidated after a merge. Thanks for your consideration!
dhardy
approved these changes
Mar 27, 2020
|
I wanted to leave this example for future reference, for anyone who needs to understand this rounding error. Thank you. |
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WeightedIndex::update_weights() uses subtraction on old_w. Rounding errors, particularly on f32, may bring total_weight to below 0. This PR makes sure a negative total_weight results in an error.
This replaces PR #955 which was invalidated after a merge. Thanks for your consideration!