This is regarding the textstat_collocations functionality in quanteda package in R. I am getting more than 2 word phrases in the output even though I am requesting only for the 2 word phrases.
The necessary processing steps are as follows (corpus1 is already created using corpus function):
collocations_two_words <- textstat_collocations(corpus1, method = "lambda", size = 2, min_count = 5, smoothing = 0.5, tolower = TRUE)
collocations_two_words <- collocations_two_words[collocations_two_words$count >= 10,]
tokens1 <- tokens(tolower(corpus1), what = "word", remove_numbers = TRUE, remove_punct = TRUE, remove_symbols = TRUE, remove_separators = TRUE, remove_url = TRUE, remove_hyphens = TRUE)
tokens1 <- tokens_remove(tokens1, stopwords("english"), padding = TRUE)
tokens2 <- tokens_compound(tokens1, pattern = collocations_two_words)
quantdfm <- dfm(tokens2, remove_punct = TRUE, remove_numbers = TRUE)
quantdfm <- dfm_trim(quantdfm, min_count = 5, min_docfreq = 5, verbose = TRUE)
When I inspect the quantdfm object (using tail(quantdfm)), I am getting more than 2 word phrases. Can someone guide me on where I might be going wrong?
Sample output looks like this: docs choosing_dark_chocolate_can eat_dark_chocolate text43979 0 0 text43980 0 0 text43981 0 0 text43982 0 0 text43983 0 0 text43984 0 0
Output of dput(head(corpus1,5)):
structure(list(documents = structure(list(texts = c("..., video game consoles, stereos, smartphone chargers, and other similar devices constantly draw power into their power supplies. Unplug all of your chargers, whether it's for a tablet or a toothbrush. Electronics with standby or \"\"sleep\"\" modes: Desktop PCs, televisions, cable boxes, DVD-ray players, alarm clocks, radios, and anything with a remote",
"...its judgment and order dated 02.05.2016 in Modern Dental College Research Centre (supra) authorizing it to oversee all statutory functions under the Act and leaving it at liberty to issue appropriate remedial directions, the impugned order is in the teeth of the recommendations of the said Committee, as communicated in its letter dated 14.05.2017",
"...' focus to the ayurveda sector, especially in oral care. A year ago, Colgate launched its first India-focused ayurvedic brand, Cibaca Vedshakti, aimed squarely at countering Dant Kanti. HUL too launched araft of ayurvedic personal care products, including toothpaste, under the Ayush brand. RIVAL TO WATCH OUT FOR Colgate Palmolive global CEO Ian",
"...founder of Increate Value Advisors. Patanjali has brought the focus back on product efficacy. Rising above the noise of advertising, products have to first deliver value to the consumers. Ghee and tooth paste are the two most popular products of Patanjali even though both of these have enough local and multinational competitors in the organised",
"The Bombay High Court today came down heavily on the Maharashtra government for not providing space and or hiring enough employees for the State Human Rights Commission. The commission has been left a toothless tiger as due to a lack of space and employees, it has not been able to hear cases of human rights violations in Maharashtra. A division"
)), .Names = "texts", row.names = c("text1", "text2", "text3",
"text4", "text5"), class = "data.frame"), metadata = structure(list(
source = "D:/Users/ajoshi/Documents/* on x86-64 by ajoshi",
created = "Fri Jan 26 19:42:21 2018"), .Names = c("source",
"created")), settings = structure(list(stopwords = NULL, collocations = NULL,
dictionary = NULL, valuetype = "glob", stem = FALSE, delimiter_word = " ",
delimiter_sentence = ".!?", delimiter_paragraph = "\n\n",
clean_tolower = TRUE, clean_remove_digits = TRUE, clean_remove_punct = TRUE,
units = "documents"), .Names = c("stopwords", "collocations",
"dictionary", "valuetype", "stem", "delimiter_word", "delimiter_sentence",
"delimiter_paragraph", "clean_tolower", "clean_remove_digits",
"clean_remove_punct", "units"), class = c("settings", "list")),
tokens = NULL), .Names = c("documents", "metadata", "settings",
"tokens"), class = c("corpus", "list"))
Output of R sessionInfo(): R version 3.4.3
other attached packages:
[1] servr_0.8 LDAvis_0.3.2 text2vec_0.5.1 stringr_1.2.0 data.table_1.10.4-3
[6] quanteda_0.99.22
loaded via a namespace (and not attached):
[1] Rcpp_0.12.15 compiler_3.4.3 pillar_1.1.0 futile.logger_1.4.3 plyr_1.8.4
[6] futile.options_1.0.0 iterators_1.0.9 tools_3.4.3 digest_0.6.14 lubridate_1.7.1
[11] tibble_1.4.1 gtable_0.2.0 lattice_0.20-35 rlang_0.1.6 Matrix_1.2-12
[16] foreach_1.4.4 fastmatch_1.1-0 mlapi_0.1.0 grid_3.4.3 R6_2.2.2
[21] RJSONIO_1.3-0 ggplot2_2.2.1 lambda.r_1.2 spacyr_0.9.3 magrittr_1.5
[26] scales_0.5.0 codetools_0.2-15 mime_0.5 colorspace_1.3-2 httpuv_1.3.5
[31] stringi_1.1.6 proxy_0.4-21 RcppParallel_4.3.20 lazyeval_0.2.1 munsell_0.4.3
This is the result on my system with quanteda v1.0.0:
require(quanteda)
txt <- c("..., video game consoles, stereos, smartphone chargers, and other similar devices constantly draw power into their power supplies. Unplug all of your chargers, whether it's for a tablet or a toothbrush. Electronics with standby or \"\"sleep\"\" modes: Desktop PCs, televisions, cable boxes, DVD-ray players, alarm clocks, radios, and anything with a remote",
"...its judgment and order dated 02.05.2016 in Modern Dental College Research Centre (supra) authorizing it to oversee all statutory functions under the Act and leaving it at liberty to issue appropriate remedial directions, the impugned order is in the teeth of the recommendations of the said Committee, as communicated in its letter dated 14.05.2017",
"...' focus to the ayurveda sector, especially in oral care. A year ago, Colgate launched its first India-focused ayurvedic brand, Cibaca Vedshakti, aimed squarely at countering Dant Kanti. HUL too launched araft of ayurvedic personal care products, including toothpaste, under the Ayush brand. RIVAL TO WATCH OUT FOR Colgate Palmolive global CEO Ian",
"...founder of Increate Value Advisors. Patanjali has brought the focus back on product efficacy. Rising above the noise of advertising, products have to first deliver value to the consumers. Ghee and tooth paste are the two most popular products of Patanjali even though both of these have enough local and multinational competitors in the organised",
"The Bombay High Court today came down heavily on the Maharashtra government for not providing space and or hiring enough employees for the State Human Rights Commission. The commission has been left a toothless tiger as due to a lack of space and employees, it has not been able to hear cases of human rights violations in Maharashtra. A division")
corp <- corpus(txt)
col <- textstat_collocations(corp, method = "lambda", size = 2, min_count = 1, smoothing = 0.5, tolower = TRUE)
head(col)
collocation count count_nested length lambda z
1 human rights 2 0 2 7.742836 3.689434
2 colgate launched 1 0 2 5.030438 3.553188
3 rights commission 1 0 2 5.030438 3.553188
4 ayurvedic brand 1 0 2 5.030438 3.553188
5 enough employees 1 0 2 5.030438 3.553188
6 launched its 1 0 2 5.030438 3.553188
table(col$length)
2
226
All the collocation have two elements. I guess that you are seeing larger collocations, because your texts are not tokenized properly.