cqp_ftable: Create a frequency table
In PolMine/rcqp.mac: Interface to the Corpus Query Protocol

Description Usage Arguments Details Value Author(s) References See Also

Create a frequency table either with a corpus or with a subcorpus. With a corpus, a frequency table is a based on two attributes (structural or positional). With a subcorpus object, a frequency table is based on two anchors (match, matchend, target, keyword) and a positional attribute for each anchor.

cqp_ftable(x, ...)

 ## S3 method for class 'cqp_corpus'
cqp_ftable(x, attribute1, attribute2, attribute1.use.id = FALSE, 
        attribute2.use.id = FALSE, structural.attribute.unique.id = FALSE, 
		subcorpus = NULL, ...)
 
 ## S3 method for class 'cqp_subcorpus'
cqp_ftable(x, anchor1, attribute1, 
        anchor2, attribute2, cutoff = 0, ...)

`x`	An rcqp object, created with `corpus` or `subcorpus`.
`attribute1`	The attribute for the modalities of the first variable of the cross-tabulation. If `x` is a subcorpus, positional attribute only.
`attribute2`	The attribute for the modalities of the second variable of the cross-tabulation. If `x` is a subcorpus, positional attribute only.
`attribute1.use.id`	If `attribute1` is a structural attribute and has values (see `cqi_structural_attribute_has_values`), switch between region ids (struc) and values (default).
`attribute2.use.id`	If attribute2 is a structural attribute and has values (see `cqi_structural_attribute_has_values`), switch between region ids (struc) and values (default).
`structural.attribute.unique.id`	Count tokens or ids. See details for more info.
`subcorpus`	Not implemented yet.
`anchor1`	The anchor for individuals of the first variable, if `x` is a subcorpus (anchor may be : match, matchend, target, keyword).
`anchor2`	The anchor for individuals of the second variable, if `x` is a subcorpus (anchor may be : match, matchend, target, keyword).
`cutoff`	Filter the frequency table.
`...`	Ignored.

Some explanations for the structural.attribute.unique.id option (see the vignette RcqpIntroduction).

Positional attributes (and structural attributes having values) are represented with their string values rather than with ids. For positional attributes, it is only a matter of presentation, since each id has its own string; but for structural attributes having values, it may entail a different counting, since these values are not unique: occurrences of phenomena belonging to different structs are then counted together if two structs have the same value. You can force the use of ids rather than string values with the attribute1.use.id and attribute2.use.id options.

Counts are made on token basis, i.e. each token of the corpus is an individual on which the two modalities (attributes) are considered. If you use two structural attributes as arguments in cqp_ftable, and one of them does not have values, then the third column counts the number of tokens. In the following example, each line gives the length (in number of tokens, third column) of each sentence (second column) in each novel represented by its title:

1
2
3

c <- corpus("DICKENS");
f <- cqp_ftable(c, "novel_title", "s")
f[1:10,]

If both structural attributes have values, you may want to count the number of times the modalities are cooccurring, rather than the total number of tokens included in these cooccurrences. For that purpose, you can use the structural.attribute.unique.id=TRUE option. In the following example, we count the number of time each head appears in each novel :

1 2	f <- cqp_ftable(c, "novel_title", "pp_h", structural.attribute.unique.id=TRUE) f[1:10,]

Here on the contrary, we count the total number of tokens in each prepositional phrase having a given head :

1 2	f <- cqp_ftable(c, "novel_title", "pp_h") f[1:10,]

A frequency table stored as a flat (3-column) dataframe : for each observed combination of modalities, the first column gives the modality in the first variable, the second column the modality in the second variable, and the third column the observed frequency of the cooccurrence.

Bernard Desgraupes - bernard.desgraupes@u-paris10.fr - University Paris-10.
Sylvain Loiseau - sylvain.loiseau@univ-paris13.fr - University Paris-13.

http://cwb.sourceforge.net/documentation.php

cqp_flist, cqp_kwic, subcorpus.

PolMine/rcqp.mac documentation built on May 28, 2019, 2:24 p.m.