Question

I am using this command (package fields)to plot my data: r.

image.plot((r),main = " RMSD", add = FALSE,legend.shrink = 0.9,
           legend.width = 1.2,  legend.mar =  5.1, graphics.reset = FALSE, 
           horizontal = FALSE, xlab = "Longitude", ylab = "Latitude", 
           bigplot = NULL, smallplot = NULL, legend.only = FALSE, 
           lab.breaks = NULL, axis.args = NULL)

But the numbers(interval) shown on the legend are like this

          0   0.1   0.2  0.3  0.4

I am grateful to anyone to tell how to change it to be something like

         0   0.05   0.1  0.15   0.2  0.25  0.3  0.35 

Answer 1

As sample data wasn’t provided, used data provided in function image.plot() help file.

x<- 1:10
y<- 1:15
z<- outer( x,y,"+") 

To set breaks manually you should use argument breaks=, then argument col= is used to provide colors (number of colors have to be one less than number of breaks). Argument lab.breaks= is used to set the same breaks also in legend.

image.plot(x,y,z,breaks=seq(2,24,2),col = terrain.colors(11),
   lab.breaks=seq(2,24,2))