Transforming kwic objects into single dfm - r

Question

I have a corpus of newspaper articles of which only specific parts are of interest for my research. I'm not happy with the results I get from classifying texts along different frames because the data contains too much noise. I therefore want to extract only the relevant parts from the documents. I was thinking of doing so by transforming several kwic objects generated by the quanteda package into a single df.
So far I've tried the following
exampletext <- c("The only reason for (the haste) which we can discern is the prospect of an Olympic medal, which is the raison d'etat of the banana republic,'' The Guardian said in an editorial under the headline ''Whatever Zola Wants. . .'' The Government made it clear it had acted promptly on the application to insure that the 5-foot-2-inch track star could qualify for the British Olympic team. The International Olympic Organization has a rule that says athletes who change their nationality must wait three years before competing for that country - a rule, however, that is often waived by the I.O.C. The British Olympic Association said it consulted with the I.O.C. before asserting Miss Budd's eligibility for the British team. ''Since Zola is now here and has a British passport she should be made to feel welcome and accepted by other British athletes,'' said Paul Dickenson, chairman of the International Athletes Club, an organization that raises money for amateur athletes and looks after their political interests. ''The thing we objected to was the way she got into the country by the Government and the Daily Mail and the commercialization exploitation associated with it.", "That left 14 countries that have joined the Soviet-led withdrawal. Albania and Iran had announced that they would not compete and did not send written notification. Bolivia, citing financial trouble, announced Sunday it would not participate.The 1972 Munich Games had the previous high number of competing countries, 122.No Protest Planned on Zola Budd YAOUNDE, Cameroon, June 4 (AP) - African countries do not plan to boycott the Los Angeles Olympics in protest of the inclusion of Zola Budd, the South African-born track star, on the British team, according to Lamine Ba, the secretary-general of the Supreme Council for Sport in Africa. Because South Africa is banned from participation in the Olympics, Miss Budd, whose father is of British descent, moved to Britain in March and was granted British citizenship.75 Olympians to Train in Atlanta ATLANTA, June 4 (AP) - About 75 Olympic athletes from six African countries and Pakistan will participate in a month-long training camp this summer in Atlanta under a program financed largely by a grant from the United States Information Agency, Anne Bassarab, a member of Mayor Andrew Young's staff, said today. The athletes, from Mozambique, Tanzania, Zambia, Zimbabwe, Uganda, Somalia and Pakistan, will arrive here June 24.")
mycorpus <- corpus(exampletext)
mycorpus.nat <- corpus(kwic(mycorpus, "nationalit*", window = 5, valuetype = "glob"))
mycorpus.cit <- corpus(kwic(mycorpus, "citizenship", window = 5, valuetype = "glob"))
mycorpus.kwic <- mycorpus.nat + mycorpus.cit
mydfm <- dfm(mycorpus.kwic)
This, however, generates a dfm that contains 4 documents instead of 2, and when both keywords are present in a document even more. I can't think of a way to bring the dfm down to the original number of documents.
Thank you for helping me out.

Answer 1

We recently added window argument to tokens_select() for this purpose:
require(quanteda)
txt <- c("The only reason for (the haste) which we can discern is the prospect of an Olympic medal, which is the raison d'etat of the banana republic,'' The Guardian said in an editorial under the headline ''Whatever Zola Wants. . .'' The Government made it clear it had acted promptly on the application to insure that the 5-foot-2-inch track star could qualify for the British Olympic team. The International Olympic Organization has a rule that says athletes who change their nationality must wait three years before competing for that country - a rule, however, that is often waived by the I.O.C. The British Olympic Association said it consulted with the I.O.C. before asserting Miss Budd's eligibility for the British team. ''Since Zola is now here and has a British passport she should be made to feel welcome and accepted by other British athletes,'' said Paul Dickenson, chairman of the International Athletes Club, an organization that raises money for amateur athletes and looks after their political interests. ''The thing we objected to was the way she got into the country by the Government and the Daily Mail and the commercialization exploitation associated with it.", "That left 14 countries that have joined the Soviet-led withdrawal. Albania and Iran had announced that they would not compete and did not send written notification. Bolivia, citing financial trouble, announced Sunday it would not participate.The 1972 Munich Games had the previous high number of competing countries, 122.No Protest Planned on Zola Budd YAOUNDE, Cameroon, June 4 (AP) - African countries do not plan to boycott the Los Angeles Olympics in protest of the inclusion of Zola Budd, the South African-born track star, on the British team, according to Lamine Ba, the secretary-general of the Supreme Council for Sport in Africa. Because South Africa is banned from participation in the Olympics, Miss Budd, whose father is of British descent, moved to Britain in March and was granted British citizenship.75 Olympians to Train in Atlanta ATLANTA, June 4 (AP) - About 75 Olympic athletes from six African countries and Pakistan will participate in a month-long training camp this summer in Atlanta under a program financed largely by a grant from the United States Information Agency, Anne Bassarab, a member of Mayor Andrew Young's staff, said today. The athletes, from Mozambique, Tanzania, Zambia, Zimbabwe, Uganda, Somalia and Pakistan, will arrive here June 24.")
toks <- tokens(txt)
mt_nat <- dfm(tokens_select(toks, "nationalit*", window = 5))
mt_cit <- dfm(tokens_select(toks, "citizenship*", window = 5))
Please make sure that you are using the latest version of Quanteda.