JSTOR_2wordcor: Plot the change over time of the correlation between one set of words and another set of words in a JSTOR DfR dataset
Description
Function to plot changes in the correlation of two set of words (two sets of 1-grams) over time. For use with JSTOR's Data for Research datasets (http://dfr.jstor.org/).
object returned by the function JSTOR_unpack1grams.
word1
One word or a vector of words, each word surrounded by standard quote marks.
word2
One word or a vector of words, each word surrounded by standard quote marks.
span
span of the loess line (controls the degree of smoothing). Default is 0.4
yearfrom
year to start the x-axis from, the minimum year to display on the plot
yearto
year to end the x-axis at, the maximum year to display on the plot
Value
Returns a ggplot object with publication year on the horizontal axis and Pearson's correlation on the vertical axis. Each point represents all the documents of a single year, point size is inversely proportional to p-value of the correlation.