要实现的正确用地是什么。

Question

r Terra软件包似乎没有一个在Terra栅格上起作用的ins.numeric（）函数？

I表示下面的hacky替代方案非常慢。有人可以提供更优雅的解决方案吗？

#set up data
  x1 = x2 = x3 = x4 = rast( nrows=180, ncols=360, nlyrs=1, xmin=-180, xmax=180, ymin=-90, ymax=90)
  x1[] = 1.0          
  x2[] = F
  x3[] = "cat"
  x4[] = as.integer(1)

#create multiband raster  
  r4 = c(x1,x2,x3,x4)

#test for numeric - the second hacky approach works SLOWLY, but hacky 
# Are the contents of my raster spooling out into memory? 
  sapply(r4, is.numeric)
  sapply(r4, function(x)is.numeric(x[]))

#test for bool - terra function works
  sapply(r4, is.bool)

#test for factor - works
  sapply(r4, is.factor)

#test for integer - second approach (terra function) works
  sapply(r4, is.integer)
  sapply(r4, is.int)

您可以做

Answer 1

sapply(r4[1], is.numeric)
#lyr.1 lyr.1 lyr.1 lyr.1 
# TRUE FALSE FALSE  TRUE