我目前正在尝试使用与线相关的图绘制降水数据(y 轴值)和使用 R 的累积排放数据(x 轴)。这两个数据都可以在我已经阅读的两个单独的 netCDF 文件中找到最终,我想做的是绘制降水作为选定位置的累积排放的函数(如下面的代码所示)。到目前为止,我已经使用了以下代码(使用 # 突出显示每个步骤):
library(raster)
library(ncdf4)
library(maps)
library(maptools)
library(rasterVis)
library(ggplot2)
library(rgdal)
library(sp)
#Geting cumulative emissions data for x-axis
ncfname <- "cumulative_emissions_1pctCO2.nc"
Model1 <- nc_open(ncfname)
print(Model1)
get <- ncvar_get(Model1, "cum_co2_emi-CanESM2") #units of terratones ofcarbon (TtC) for x-axis
print(get)
Year <- ncvar_get(Model1, "time") #140 years
#Getting Model data for extreme precipitation (units of millimeters/day)for y-axis
ncfname1 <- "MaxPrecCCCMACanESM21pctCO2.nc"
Model2 <- nc_open(ncfname1)
print(Model2)
get1 <- ncvar_get(Model2, "onedaymax") #units of millimeters/day
print(get1)
#Reading in latitude, longitude and time from this file:
latitude <- ncvar_get(Model2, "lat") #64 degrees latitude
longitude <- ncvar_get(Model2, "lon") #128 degrees longitude
Year1 <- ncvar_get(Model2, "Year") #140 years
#Plotting attempt
r_brick <- brick(get, xmn=min(latitude), xmx=max(latitude),
ymn=min(longitude), ymx=max(longitude), crs=CRS("+proj=longlat +ellps=WGS84
+datum=WGS84 +no_defs+ towgs84=0,0,0"))
randompointlon <- 30 #selecting a longitude
randompointlat <- -5 #selecting a latitude
Hope <- extract(r_brick,
SpatialPoints(cbind(randompointlon,randompointlat)),method = 'simple')
df <- data.frame(cumulativeemissions=seq(from = 1, to = 140, by = 1),
Precipitation=t(Hope))
ggplot(data = df, aes(x = get, y = Precipitation,
group=1))+geom_line()+ggtitle("One-day maximum precipitation (mm/day)
for random location for CanESM2 1pctCO2 as a function of cumulative
emissions")
print(Model1) 产生以下结果(我读入变量 #2 以供现在使用):
文件累积排放量_1pctCO2.nc (NC_FORMAT_NETCDF4):
14 variables (excluding dimension variables):
float cum_co2_emi-BNU-ESM[time] (Contiguous storage)
long_name: Cumulative carbon emissions for BNU-ESM
units: Tt C
float cum_co2_emi-CanESM2[time] (Contiguous storage)
long_name: Cumulative carbon emissions for CanESM2
units: Tt C
float cum_co2_emi-CESM1-BGC[time] (Contiguous storage)
long_name: Cumulative carbon emissions for CESM1-BGC
units: Tt C
float cum_co2_emi-HadGEM2-ES[time] (Contiguous storage)
long_name: Cumulative carbon emissions for HadGEM2-ES
units: Tt C
float cum_co2_emi-inmcm4[time] (Contiguous storage)
long_name: Cumulative carbon emissions for inmcm4
units: Tt C
float cum_co2_emi-IPSL-CM5A-LR[time] (Contiguous storage)
long_name: Cumulative carbon emissions for IPSL-CM5A-LR
units: Tt C
float cum_co2_emi-IPSL-CM5A-MR[time] (Contiguous storage)
long_name: Cumulative carbon emissions for IPSL-CM5A-MR
units: Tt C
float cum_co2_emi-IPSL-CM5B-LR[time] (Contiguous storage)
long_name: Cumulative carbon emissions for IPSL-CM5B-LR
units: Tt C
float cum_co2_emi-MIROC-ESM[time] (Contiguous storage)
long_name: Cumulative carbon emissions for MIROC-ESM
units: Tt C
float cum_co2_emi-MPI-ESM-LR[time] (Contiguous storage)
long_name: Cumulative carbon emissions for MPI-ESM-LR
units: Tt C
float cum_co2_emi-MPI-ESM-MR[time] (Contiguous storage)
long_name: Cumulative carbon emissions for MPI-ESM-MR
units: Tt C
float cum_co2_emi-NorESM1-ME[time] (Contiguous storage)
long_name: Cumulative carbon emissions for NorESM1-ME
units: Tt C
float cum_co2_emi-GFDL-ESM2G[time] (Contiguous storage)
long_name: Cumulative carbon emissions for GFDL-ESM2G
units: Tt C
float cum_co2_emi-GFDL-ESM2M[time] (Contiguous storage)
long_name: Cumulative carbon emissions for GFDL-ESM2M
units: Tt C
1 dimensions:
time Size:140
units: years since 0-1-1 0:0:0
long_name: time
standard_name: time
calender: noleap
4 global attributes:
description: Cumulative carbon emissions for the 1pctCO2 scenario from the CMIP5 dataset.
history: Created Fri Jul 21 14:50:39 2017
source: CMIP5 archieve
print(Model2) 产生以下结果:
文件 MaxPrecCCCMACanESM21pctCO2.nc (NC_FORMAT_NETCDF4):
3 variables (excluding dimension variables):
double onedaymax[lon,lat,time] (Contiguous storage)
units: mm/day
double fivedaymax[lon,lat,time] (Contiguous storage)
units: mm/day
short Year[time] (Contiguous storage)
3 dimensions:
time Size:140
lat Size:64
units: degree North
lon Size:128
units: degree East
3 global attributes:
description: Annual global maximum precipitation from the CanESM2 1pctCO2 scenario
history: Created Mon Jun 4 11:24:02 2018
contact: rain1290@aim.com
所以,总的来说,这就是我想要实现的目标,但我不确定我在 ggplot 函数中所做的是否是正确的方法。
对此的任何帮助将不胜感激!
谢谢