TWiki> FST Web>FstQuickTour>RandEquivalentDoc (2018-04-27, MichaelRiley)

# RandEquivalent

## Description

This operation test is two FSTs are equivalent by randomly generating N paths alternatively in each of the two FSTs.

For each randomly generated path, the algorithm computes for each of the two FSTs the sum of the weights of all the successful paths sharing the same input and output labels as the considered randomly generated path and checks that these two values are within 'delta'.

The random generation can be specified in the same as for the RandGen operation.

## Usage

 ```template bool RandEquivalent(const Fst &fst1, const Fst &fst2, ssize_t num_paths, float delta = kDelta, int seed = time(0), int path_length = INT_MAX); ``` ```template bool RandEquivalent(const Fst &fst1, const Fst &fst2, ssize_t num_paths, float delta, const RandGenOptions &opts); ``` ```fstequivalent --random [-npath=\$n] [--delta=\$delta] [--seed=\$seed] [--max_length=\$max_length] in1.fst in2.fst ```

## Example

 `A` `B`  ```RandEquivalent(A, B, npaths, kDelta, RandGenOptions<ArcSelector>());

fstequivalent --random --npath=\$npaths a.fst b.fst
```

 `ArcSelector` `npaths` `RandEquivalent(A, B)` `UniformArcSelector` `10` `false` `LogProbArcSelector` `10` `true` `1000000` `false` png randequiv1.png r4 r3 r2 r1 manage 11.3 K 2009-03-27 - 20:17 CyrilAllauzen RandEquivalent: first input FST png randequiv2.png r3 r2 r1 manage 11.1 K 2009-03-27 - 20:38 CyrilAllauzen RandEquivalent: second input FST