---
name: "ngramperplexity"
section: "1"
platform: "linux"
package: "libngram-tools"
version: "1.3.2-3"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/ngramperplexity"
---

# ngramperplexity(1)

Apply n-gram model to input fst archive.

## NAME

ngramperplexity - Apply n-gram model to input fst archive.

## DESCRIPTION

Apply n-gram model to input fst archive.

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  ## SYNOPSIS

ngramperplexity \[--options\] ngram.fst \[in.far \[out.txt\]\]

## OPTIONS

**--OOV\_class\_size**: type = double, default = 10000

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  Number of members of OOV class

**--OOV\_probability**: type = double, default = 0

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  Unigram probability for OOVs

**--OOV\_symbol**: type = string, default = ""

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  Existing symbol for OOV class

**--context\_pattern**: type = string, default = ""

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  Restrict perplexity computation to contexts defined by pattern (default: no restriction)

**--use\_phimatcher**: type = bool, default = false

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  Use phi matcher and composition

**--help**: type = bool, default = false

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  show usage information

**--helpshort**: type = bool, default = false

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  show brief usage information

**--tmpdir**: type = string, default = "/tmp"

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  temporary directory

**--v**: type = int32, default = 0

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  verbosity level

**--fst\_align**: type = bool, default = false

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  Write FST data aligned where appropriate

**--fst\_default\_cache\_gc**: type = bool, default = true

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  Enable garbage collection of cache

**--fst\_default\_cache\_gc\_limit**: type = int64, default = 1048576

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  Cache byte size that triggers garbage collection

**--fst\_read\_mode**: type = string, default = "read"

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  Default file reading mode for mappable files

**--fst\_verify\_properties**: type = bool, default = false

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  Verify FST properties queried by TestProperties

**--save\_relabel\_ipairs**: type = string, default = ""

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  Save input relabel pairs to file

**--save\_relabel\_opairs**: type = string, default = ""

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  Save output relabel pairs to file

**--end\_symbol**: type = string, default = "\</s\>"

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  Class label for sentence start

**--start\_symbol**: type = string, default = "\<s\>"

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  Class label for sentence start

**--fst\_compat\_symbols**: type = bool, default = true

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  Require symbol tables to match when appropriate

**--fst\_field\_separator**: type = string, default = "      "

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  Set of characters used as a separator between printed fields

**--fst\_error\_fatal**: type = bool, default = true

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  FST errors are fatal; o.w. return objects flagged as bad: e.g., FSTs: kError property set, FST weights: not a Member()

**--ngram\_error\_fatal**: type = bool, default = true

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  NGram errors are fatal; o.w. return objects flagged as bad:  e.g., NGramModel::Error() returns true.

**--fst\_weight\_parentheses**: type = string, default = ""

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  Characters enclosing the first weight of a printed composite weight (e.g., pair weight, tuple weight and derived classes) to ensure proper I/O of nested composite weights; must have size 0 (none) or 2 (open and close parenthesis)

**--fst\_weight\_separator**: type = string, default = ","

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  Character separator between printed composite weights; must be a single character