When you define your version of nrow, are you extending the DataFrames version as in the following?
DataFrames.nrow(df::MyDataFrame) = ... If not, you are defining your own nrow that is different than the one in DataFrames. On Fri, Mar 27, 2015 at 12:45 PM, <kevin.dale.sm...@gmail.com> wrote: > I'm trying to extend DataFrames so that I can include metadata on the > dataframe and the columns. Unfortunately, from the way I understand how > Julia works, this is not an easy task. It seams as though I pretty much > have to copy the existing dataframes.jl file and replace all of the > "DataFrame" references with "MyDataFrame", then add in the metadata parts > where needed (or use composition and proxy all of the DataFrame > interfaces). This method seems to work for some things (it works with > Gadfly), however, I can't seem to get ncol and nrow to work properly. When > I try to do "size(mydf)", I get the following error: > > `nrow` has no method matching nrow(::MyDataFrame) > > However, if I do "methods(nrow)", it displays this: > > nrow(df::MyDataFrame) > > Which is exactly what the previous message said didn't exist. I'm a > little puzzled as to why DataFrames' original nrow doesn't show up in that > output as well since it is exported. When I do a "using DataFrames" in > this same session. I get the following warning. > > Warning: using DataFrames.nrow in module Main conflicts with an > existing identifier. > > I think it's safe to say that I'm pretty confused at this point. I'd > appreciate it if someone could clarify how extending existing structures is > supposed to work. > > >
