I am quite new to R, I am trying to do a Corresp analysis (MASS package) on summarized data. While the output shows row and column score, the resulting biplot shows the column scores as zero, making the plot unreadable (all values arranged by row scores in an expected manner, but flat along the column scores).
the code is
corresp(some_data)
biplot(corresp(some_data, nf = 2))
I would be grateful for any suggestions as to what I'm doing wrong and how to amend this, thanks in advance! Martin
link to the image the plot corresp results
As suggested here:
http://www.statsoft.com/textbook/correspondence-analysis
the biplot actually depicts distributions of the row/column variables over 2 extracted dimensions where the variables' dependency is "the sharpest".
Looks like in your case a good deal of dependencies is concentrated along just one dimension, while the second dimension is already mush less significant.
It does not seem, however, that you relationships are weak. On the contrary, looking at your graph, one can observe the red (column) variable's interception with 2 distinct regions of the other variable values.
Makes sense?
Regards,
Igor