我有从日常气候数据创建的栅格堆栈。可以在这里找到:当应用于栅格堆栈时,栅格计算仅返回一个图层
#!/bin/bash
wget -nc -c -nd http://northwestknowledge.net/metdata/data/tmmx_1982.nc
目标是从这些日常记录中获得每月95%的温度值。每当我使用raster
包中的calc
时,它只返回一层而不是12(例如,12个月)我错过了什么?
library(raster)
library(tidyverse)
library(lubridate)
file = "../data/raw/climate/tmmx_1982.nc "
rstr <- raster(file)
> rstr class : RasterBrick dimensions : 585, 1386, 810810, 366 (nrow, ncol, ncell, nlayers) resolution : 0.04166667, 0.04166667 (x, y) extent : -124.793, -67.043, 25.04186, 49.41686 (xmin, xmax, ymin, ymax) coord. ref. : +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0 data source : in memory names : layer.1, layer.2, layer.3, layer.4, layer.5, layer.6, layer.7, layer.8, layer.9, layer.10, layer.11, layer.12, layer.13, layer.14, layer.15, ... min values : 1.3268673, 0.7221603, 1.8519223, 1.6214808, 0.8629752, 1.1126643, 1.8769895, 0.9587604, 1.7360761, 2.1099827, 2.1147265, 1.8696048, 1.7619936, 2.0253942, 2.6840794, ... max values : 73.20462, 60.35675, 64.68890, 53.11994, 60.15675, 55.91125, 77.29095, 64.39179, 48.26004, 64.70559, 79.85970, 62.31242, 53.89768, 52.15949, 80.23198, ...
date_seq <- date_seq[1:nlayers(rstr)]
month_seq <- month(date_seq)
mean_tmp <- stackApply(rstr, month_seq, fun = mean)
> mean_tmp class : RasterBrick dimensions : 585, 1386, 810810, 12 (nrow, ncol, ncell, nlayers) resolution : 0.04166667, 0.04166667 (x, y) extent : -124.793, -67.043, 25.04186, 49.41686 (xmin, xmax, ymin, ymax) coord. ref. : +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0 data source : /tmp/RtmpYf4pQe/raster/r_tmp_2017-09-25_182536_48012_88372.grd names : index_1, index_2, index_3, index_4, index_5, index_6, index_7, index_8, index_9, index_10, index_11, index_12 min values : 4.586111, 5.656802, 6.444234, 6.875973, 6.281896, 4.495534, 5.081545, 4.396824, 4.316368, 6.413400, 4.233641, 3.119827 max values : 49.12178, 47.61632, 44.70796, 47.57829, 46.97714, 51.61986, 37.77228, 51.30043, 42.51572, 36.86453, 37.96615, 52.15552
mean_90thtmp <- calc(mean_tmp, forceapply = TRUE,
fun = function(x) {quantile(x, probs = 0.90, na.rm = TRUE) })
> mean_90thtmp class : RasterLayer dimensions : 585, 1386, 810810 (nrow, ncol, ncell) resolution : 0.04166667, 0.04166667 (x, y) extent : -124.793, -67.043, 25.04186, 49.41686 (xmin, xmax, ymin, ymax) coord. ref. : +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0 data source : in memory names : layer values : 8.84197, 50.52144 (min, max)
建议都非常感谢!
谢谢!
由于您正在计算每月平均值的第90百分位数,因此您将获得单个图层。我不太确定你为什么计算平均值。我认为你需要在stackApply函数中运行分位数函数,或者在一个循环中运行分位数函数,在这个循环中你从堆栈中为每个月的每日值进行分类。当我尝试使用stackApply方法时出现错误,但我会尝试更多的想法并提交答案。 –
理想情况下,这将是每天的手段,但由于我无法创建第95百分位的每月图像,我想我会先找出解决方案。我试着在stackApply里面的每日图像上运行这个函数,但是一直返回一个错误。我真的被卡住了,任何建议都会非常有帮助。谢谢! –