Question

我有一个用图像函数

绘制的网格字段

df <- datainSUB

yr mo dy hr   lon   lat cell  sst  avg moavg
1900  6  5 17 -73.5 -60.5   83  2.4 2.15  3.15
1900  6  7 17 -74.5 -60.5   83  3.9 2.15  3.15
1900  8 17 17 -70.5 -60.5   83 -0.9 2.15  0.60
1900  8 18 17 -73.5 -60.5   83  2.1 2.15  0.60
1900  9 20 17 -71.5 -60.5   83  0.2 2.15  2.20
1900  9 21 17 -74.5 -61.5   83  1.6 2.15  2.20

gridplot <- function(df){
    pdf(paste(df$mo,".pdf"))
    # Compute the ordered x- and y-values
    LON <- seq(-180, 180, by = space)
    LAT <- seq(-90, 90, by = space)

    # Build the matrix to be plotted
    moavg <- matrix(NA, nrow=length(LON), ncol=length(LAT))
    moavg[cbind(match(round(df$lon, -1), LON), match(round(df$lat, -1), LAT))] <- df$moavg

    # Plot the image
    image(LON, LAT, moavg)
    map(add=T,col="saddlebrown",interior = FALSE, database="world")
    dev.off()
}

我想在情节中添加颜色图例，但我不知道该怎么做。也许ggplot更好？

非常感谢

Answer 1

绘制数据后添加以下行：

legend(x="topright", "your legend goes here", fill="saddlebrown")

绘制网格字段

1 个答案: