title: Creating a continuous density heatmap of 2D scatter data in R with each column of dataframe coloured differently
body: <p>I am curious if there's a way to improve upon the answers mentioned in <a href="https://stackoverflow.com/questions/7073315/how-do-i-create-a-continuous-density-heatmap-of-2d-scatter-data-in-r?answertab=active#tab-top">1</a><br>
  For example,<br>
  1) Can the x and y columns of the data-frame be colored differently rather than red or using a color gradient?. And as specified in ggplot2 documentation, I don't want color the columns according to a factor<br>
  2) Furthermore, can the shape of points be altered respectively for each of the columns in the data-fame (e.g. triangles for x values and round for y values)<br>
  To achieve the same, afaik, I tried to plot each column separately by tweaking the code mentioned in <a href="https://stackoverflow.com/questions/7073315/how-do-i-create-a-continuous-density-heatmap-of-2d-scatter-data-in-r?answertab=active#tab-top">1</a><br>
  All i got was the same plot with red color for each point with a failure to change the shape when using the aes() function for each column separately.</p>
  
  <p>Thanks and Regards,<br>
  Yogesh</p>