Local minima vs local minimum

Course Q&A Machine Learning Specialization Supervised ML: Regression and Classification
1

Please give me a comparison between local minimum and local minima.

week 1

2

@farhana_hossain ‘minima’ of course, is plural, meaning there is more then one. Minimum (or typically we talk about a ‘global minimum’) means the lowest point of all.

You can try to imagine a mountain range, where between mountains, you will have valleys, likely many of them-- These would be your ‘minima’.

Yet one of these valleys would be deepest of them all-- This is your ‘minimum’.

… Or… Just reading the way you phrased your question again: local minimum (one, of many minima-- plus since it is local, it means it is the lowest point in the region under study).

4

Same concept, but:

  • Minima is plural
  • Minimum is singular.

If you have a convex cost function, then there is only one minimum, and you would use the singular form.

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