2012-02-27 94 views
5

好日子大家,GGPLOT2和地图:geom_point和annotation_raster的位置偏移

使用下面的代码,我可以用ggmap成功检索从谷歌的光栅,绘制一个annotation_raster使用ggplot2,和情节的网站地方如在上面的红点的栅格图层。在情节上,职位不太匹配(他们应该跟随海岸线)。我知道我的网站的位置是正确的,因为当我将数据作为KML文件上传到Google地球时,它们绘制了它们应该在的位置。

建议将不胜感激。

此代码将按原样运行...请注意,您需要开发版本为ggplot2,该版本可在github上获得。要安装:

# install.packages("devtools") 
library(devtools) 
install_github("ggplot2") 

及代码:

library(ggplot2) 
library(ggmap) 
library(grDevices) 
theme_set(theme_bw()) 

# Some coordinates of points to plot: 
siteLat = c(-22.94414, -22.67119, -29.25241, -30.31181, -32.80670, -33.01054, -32.75833, -  33.36068, -31.81708, -32.09185, -32.31667, -34.13667, -34.05016, -33.91847, -34.13525, -34.12811, -34.10399, -34.16342, -34.41459, -34.58786, -34.83353, -34.37150, -34.40278, -34.17091, -34.08565, -34.04896, -33.98066, -34.02448, -34.20667, -34.05889, -33.97362, -33.99125, -33.28611, -33.02407, -33.01798, -32.99316, -31.09704, -31.05000, -30.91622, -30.70735, -30.28722, -30.27389, -29.86476, -29.54501, -29.49660, -29.28056, -28.80467, -27.42472) 
siteLon = c(14.50175, 14.52134, 16.86710, 17.26951, 17.88522, 17.95063, 18.02778, 18.15731, 18.23065, 18.30262, 18.32222, 18.32674, 18.34971, 18.38217, 18.43592, 18.45077, 18.48364, 18.85908, 19.25493, 19.33971, 20.00439, 21.43518, 21.73972, 22.12749, 23.05532, 23.37925, 23.64567, 23.89933, 24.77944, 25.58889, 25.64724, 25.67788, 27.48889, 27.91626, 27.92182, 27.95036, 30.18395, 30.21666, 30.32982, 30.48474, 30.76026, 30.83556, 31.04479, 31.21662, 31.24665, 31.44403, 32.07567, 32.73333) 
siteName = c(seq(1:length(siteLon))) 
sites <- as.data.frame(cbind(siteLat, siteLon, siteName)) 

# specify raster's approximate coordinates: 
lats = c(-35, -20) 
lons = c(10, 35) 

SAMap <- GetMap.bbox(lons, lats, maptype = "satellite") 

# extract "real" coords of raster: 
lonr <- c(SAMap$BBOX$ll[2], SAMap$BBOX$ur[2]) 
latr <- c(SAMap$BBOX$ll[1], SAMap$BBOX$ur[1]) 

# extract raster fill data: 
h_raster <- as.raster(SAMap$myTile) 

# plot using annotation_raster: 
g <- ggplot(sites, aes(siteLon, siteLat)) 
g + annotation_raster(h_raster, lonr[1], lonr[2], latr[1], latr[2]) + 
    geom_point(aes(x = siteLon, y = siteLat), colour = "red", data = sites) + 
    scale_x_continuous(limits = lonr) + 
    scale_y_continuous(limits = latr) 

(对不起,我不能,因为我是新来张贴图片)。

+0

这并不在我的机器上运行。我怀疑你还需要包含'library(raster)'。即使如此,仍无法找到'annotation_raster'。这是哪个包(和版本)? – Andrie 2012-02-27 13:27:13

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我想你需要一个实验性的'ggplot2'版本,请参阅https://github.com/hadley/ggplot2以获取安装信息。 – 2012-02-27 14:02:34

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我认为'as.raster()'住在'library(grDevices)'中。 'annotation_raster'在'ggplot2'版本0.9.0中。将更新顶部的代码。 – 2012-02-27 14:11:29

回答