plot density of a discrete annotation along a continuou values
giotto object
the column name of discrete annotation in cell metadata
the column name of continuous values in cell metadata
spatial unit (e.g. "cell")
feature type (e.g. "rna", "dna", "protein")
logical. show plot
logical. return ggplot object
logical. save the plot
list of saving parameters, see showSaveParameters
default save name for saving, don't change, change save_name in save_param