Question:

I cannot find a straightforward way to make a nice image plot in R, but in polar coordinates. I'm basically attempting to find a R equivalent for the 'polarplot3d' function in MATLAB. I've been playing around with ggplot2 package but without much luck. Am I missing a package that contains functionality for what I'm attempting? thanks in advance for any pointers.

Ok, I'm trying to be more clear about what I'm trying to do. Lets say I want to define a polar coordinate grid, increments in the radial direction are 50m and 2.5 degrees in theta. This should look like a dartboard.

My data (r and angle in below code) are correspond to a radial distance measure and an angle. My desired z-value is the counts of a bivariate histogram between r and angle within the increments described above defining the grid.

My data is like the following:

```
# synthetic data for angle and distance #
angle <- rnorm(500,mean=90,sd=15)
r <- rnorm(500,mean=700,sd=200)
# bivariate histogram #
observations <- table(cut(angle,breaks=c(seq(0,360,by=2.5))),cut(r,breaks=c(seq(0,1400,by=50))))
# the 'z' data are in observations for each bin of bivariate histogram #
# hot to plot a polar coord image? #
```

Answer1:It's <em>very</em> slow to render on my system, but

```
library(reshape2)
library(ggplot2)
mm <- melt(counts)
ggplot(mm,aes(Var1,Var2,fill=value))+geom_tile()+coord_polar()
ggsave("polar1.png")
```

appears to work.

<img alt="enter image description here" class="b-lazy" data-src="https://i.stack.imgur.com/joz6m.png" data-original="https://i.stack.imgur.com/joz6m.png" src="https://etrip.eimg.top/images/2019/05/07/timg.gif" />

Answer2:I think the following could work. Use `mapproject()`

from the `maproj`

library to transform my `xy`

coordinates acording to a polar projection (or another), Then use `as.image()`

(from `fields`

package) function to build a image object from my new coordiantes and my Z values. Eventually use `image.plot()`

.

```
library("mapproj")
xyProj <- mapproject(x, y, projection="conic", parameters=-90)
library("fields")
im <- as.image(z, x=xyProj)
image.plot(im)
```