Row and column labels are backwards in covert(...to-"lsa")

[BobMuenchen]

The convert function does the right thing when it takes a dfm "to=lsa". However, the row and column headings are backwards and need to be reversed. Here is an example from the lsa help file showing what he calls a "dtm" is what most packages would call a "tdm" since the first letter usually refers to rows in R:

> library("lsa")
> ldir = tempfile()
> dir.create(ldir)
> write( c("human", "interface", "computer"), file=paste(ldir, "c1", sep="/"))
> write( c("survey", "user", "computer", "system", "response", "time"), file=paste(ldir, "c2", sep="/"))
> write( c("EPS", "user", "interface", "system"), file=paste(ldir, "c3", sep="/"))
> write( c("system", "human", "system", "EPS"), file=paste(ldir, "c4", sep="/"))
> write( c("user", "response", "time"), file=paste(ldir, "c5", sep="/"))
> write( c("trees"), file=paste(ldir, "m1", sep="/"))
> write( c("graph", "trees"), file=paste(ldir, "m2", sep="/"))
> write( c("graph", "minors", "trees"), file=paste(ldir, "m3", sep="/"))
> write( c("graph", "minors", "survey"), file=paste(ldir, "m4", sep="/"))
> 
> # -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
> # generate doc term matrix from landauer files
> 
> dtm = textmatrix(ldir, minWordLength=1)
> dtm
           docs  <===================Note how this refers to documents
terms       c1 c2 c3 c4 c5 m1 m2 m3 m4
  computer   1  1  0  0  0  0  0  0  0
  human      1  0  0  1  0  0  0  0  0
  interface  1  0  1  0  0  0  0  0  0
  response   0  1  0  0  1  0  0  0  0
  survey     0  1  0  0  0  0  0  0  1
  system     0  1  1  2  0  0  0  0  0
  time       0  1  0  0  1  0  0  0  0
  user       0  1  1  0  1  0  0  0  0
  eps        0  0  1  1  0  0  0  0  0
  trees      0  0  0  0  0  1  1  1  0
  graph      0  0  0  0  0  0  1  1  1
  minors     0  0  0  0  0  0  0  1  1

Here's a dfm created by quanteda:

> music_dfm_cleaned[1:10,1:5]
Document-feature matrix of: 10 documents, 5 features (86% sparse).
10 x 5 sparse Matrix of class "dfmSparse"
       light battery power great cost
text1      1       0     0     0    0
text2      0       1     1     1    0
text3      0       0     0     0    1
text4      0       0     0     0    0
text5      0       0     0     0    0
text6      0       1     0     0    0
text7      0       0     0     0    0
text8      0       0     0     0    0
text9      0       0     0     1    0
text10     0       0     0     0    0


...and now converted to lsa:

> library("quanteda")
> library("lsa")
> music_tdm <- convert(music_dfm_cleaned, to = "lsa")  # <===I call it tdm, don't let that confuse you!
> music_tdm[1:10,1:5]
         terms   <==================so "terms" should be replaced with "docs" & vice versa
docs      text1 text2 text3 text4 text5
  light       1     0     0     0     0
  battery     0     1     0     0     0
  power       0     1     0     0     0
  great       0     1     0     0     0
  cost        0     0     1     0     0
  size        0     0     1     0     0
  all_my      0     0     0     1     0
  cds         0     0     0     1     0
  palm        0     0     0     1     0
  hand        0     0     0     1     0
``

[kbenoit]

Fixed now - thanks for finding this!