[R] Calculating proportions from a data frame rather than a table

[John Kane]

What am I missing here?

Cannot you just create the table from the data.frame
and apply prop.table()to it?

--- Farrel Buchinsky <fjbuch at gmail.com> wrote:

> When one has raw data it is easy to create a table
> of one variable against
> another and then calculate proportions
> For example
> a.nice.table<-table(a,b)
> prop.table(a.nice.table,1)
> 
> However, I looked at several papers and created a
> data frame of the
> aggregate data. That means I acually created a table
> except it is a data
> frame. The first column lists the name of the first
> author and the year.
> I cannot find how to convert the data frame to a
> table so I can use great
> functions such as prop.table and margin.table.
> 
> Alas I tried, rowSums but it provides lousy output
> without listing the names
> of th papers.
> I have thought of going through the reshape package
> but I suspect that there
> is an easier way to convert a data frame to a table.
> Is there?
> 
> -- 
> Farrel Buchinsky