[Gnuplot-info] simple heatmap plot

[Peter C. <pe...@ho...>]

I am attempting to plot a simple heatmap on a png.  The data will 
consist of:
      lat,lon,value - where value is a measurement taken at a particular 
lat/lon
      lat,lon,0 - where lat,lon represent the boundary of the area, and 
0 is a hard coded value to print a specific color

I have tried
plot 'boundary.csv' with lines
plot 'boundary.csv' using 1:2 with lines
plot 'boundary.csv' matrix using 1:2:3 with points
splot 'boundary.csv' matrix with image

I can seem to draw a simple geographic boundary :(

Here is the boundary dataset:
-118.4416963421,34.2684862765,-80
-118.5296361373,34.0505446952,-80
-118.3178973599,33.966252909,-80
-118.1589688575,34.1702770376,-80
-118.4416963421,34.2684862765,-80