frequenciesOverTime       Plot frequency of query expressions over time
frequenciesOverDomains    Box plot frequency of query expressions per topic domain
conditionsOverTime        Plot frequency of query expressions over time under different conditions
alternativesOverTime      Plot proportion of alternative spellings/variants over time
regional                  Map plot regional frequencies of query expression
mosaicplot                Visualize frequencies of alternative query terms in relation to other variables
rcharts-highcharts        Visualize term frqequencies over time with interactive HTML and JavaScript elements