I have to plot the temperature map of a cross-section inside a cylinder for which I use this data. When I plot the data as a heat map in Gnuplot all I get is the following figure. My heat map is supposed to be a quarter-circle. The coordinates in my data file correspond only to a quarter circle. But Gnuplot gives me a square. How do I get a quarter-circle heat map?
MWE
set pm3d map interpolate 0,0
set dgrid3d
splot 'Temp.dat' using 1:2:3