使用 RColorBrewer 绘图时出错

Question

我正在尝试根据栅格数据绘制地图。我正在使用此代码：

library(raster)
library(rgdal)
library(classInt)
library(RColorBrewer)

NDII = raster("G:\\Sheyenne\\image_differencing\\NDII\\differenced.tif")
value.vector = values(NDII)
breaks.qt = classIntervals(value.vector, n = 6, style = "jenks", intervalClosure = "right")
print (plot(NDII, breaks=breaks.qt$brks, col = brewer.pal(6, "Set1")))

但这会返回：

Error in print(plot(NDII, breaks = breaks.qt$brks, col = brewer.pal(6, : error in evaluating the argument 'x' in selecting a method for function 'print': Error in .asRaster(x, col, breaks, zrange, colNA, alpha = alpha) : could not find function "brewer.pal"

Answer 1

您没有提供可重现的示例，我也无法重现您的错误。 以下代码与您使用 R 徽标的可重现示例作为光栅的代码相同（并且使用 NDII[] 而不是将 values(NDII) 存储在变量中的快捷方式）对我来说很好......

library(raster)
library(rgdal)
library(classInt)
library(RColorBrewer)

NDII = raster(system.file("external/rlogo.grd", package="raster"))
# next line is really slow, I'd advise to run crop(NDII, extent(0,20,0,20)) 
# before to make quick tests
breaks.qt = classIntervals(NDII[], n = 6, style = "jenks", 
                           intervalClosure = "right")
plot(NDII, breaks=breaks.qt$brks, col = brewer.pal(6, "Set1"))

您是否使用此代码重现您的错误？也许您可以开始一个新的、全新的会话？