[R] Using image/contour with unevenly spaced data...

[Jason Rupert]

Is it possible to plot unevenly spaced data with image/contour function?  

Below is an example of the type uneven data that I'm trying to plot with 
image/contour functions.  For example, I would like to have the x-distance on 
the x-axis and y-distance on the y-axis and then the temperature values 
determine the color used.  Unfortunately this data was sampled such that it is 
not evenly spaced on a Cartesian plot.  


I was hoping that image(temp_samples) or contour(temp_samples) or something 
similar would work, but my attempts didn't succeed.  


Thanks for any feedback insights and hints...


hyp_distance<-seq(1,15)
angle_deg_val<-seq(0,15)


x_distance_val<-NULL
y_distance_val<-NULL

for(ii in 1:length(hyp_distance))
{
        for(jj in 1:length(angle_deg_val))
        {
                x_distance_tmp<-hyp_distance[ii]*cos(angle_deg_val[jj]*pi/180)
                y_distance_tmp<-hyp_distance[ii]*sin(angle_deg_val[jj]*pi/180)
                
                x_distance_val<-c(x_distance_val, x_distance_tmp)
                y_distance_val<-c(y_distance_val, y_distance_tmp)
        }
        
}

temperature_vals<-rnorm(length(x_distance_val), 75, 2.2)

temp_samples<-cbind(x_distance_val, y_distance_val, temperature_vals)