使用“ filled.contour”绘制地图

Question

I am plotting a map in R using 'filled.contour()' and I do not understand why this function switches the x,y axis. I have:

x=1:20
y=1:10
z=array(seq(1,2000,1),dim=c(length(y),length(x)) )
filled.contour(x,y,z,plot.title=title(main="Test",xlab="X",ylab="Y")  )

Error in .filled.contour(x, y, z, levels, col) : dimension mismatch

but if I enter:

z=array(seq(1,2000,1),dim=c(length(x),length(y)) )

it plots the map correctly. All documentation about arrays shows that 'dim' is defined as dim(y,x) Am I missing something?

Answer 1

The issue is what you are passing through the contour function. You have to pass x and y in the order that you set z as the dimensions of. So the reason that z=array(seq(1,2000,1),dim=c(length(x),length(y))) worked is because you called for

filled.contour(**x**,**y**,z,plot.title=title(main="Test",xlab="X",ylab="Y"))

The code below runs as you would hope.

x=1:20
y=1:10
z=array(seq(1,2000,1),dim=c(length(y),length(x)))
filled.contour(y,x,z,plot.title=title(main="Test",xlab="X",ylab="Y")  )