Takes in an object, and converts it to a grob based on inputted aesthetics arguments.
convert_to_grob(x, height, width, aes_list = ga_list())A grob of x with aesthetics based on the aes_list parameter.
The object which needs to be converted to a grob. Must be either:
A data.frame/matrix, the file name of a .png image, a character string, a
vector, a ggplot object, or NA (for an empty grob).
The numeric height in mm of the desired grob.
The numeric width in mm of the desired grob.
The list outputted by ga_list which contains elements
to adjust aesthetics to the grob of x. Different type of grobs have
different types of elements of this list which will affect its aesthetics.
Possible elements for character strings, matrices and images can be found in ga_list.