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FilterRules

FilterRules

FilterRules[rules,patt]

filters the list rules by picking out only those rules whose left-hand sides match patt.

FilterRules[rules,{patt₁,patt₂,…}]

picks out rules whose left-hand sides match any of the patt_i.

Details

The rules in the list rules can be either -> or :> rules.
If any of the patt_i is a rule of the form lhs->rhs, then it is treated the same as lhs.
If patt_i is a string, it will also match a symbol whose name is the string.
FilterRules[rules,Except[patt]] gives all rules except those whose left-hand sides match patt.

Examples

Basic Examples (2)

Wolfram Language code: FilterRules[{a -> 1, b -> 2, c -> 3}, {b, a}]

Filter for options that appear in Plot:

Wolfram Language code: FilterRules[{PlotRange -> 3, MaxIterations -> 5}, Options[Plot]]

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