从 R 中的 .nc 文件按时间绘制生物量数据

Question

我有一个浮游生物生物量的 .nc 文件，“经度、纬度、时间”尺寸为“180、125 和 480”。时间数据是数字，以 1,2,3,....480 开头。它代表 1980-2000 之间的年份。我想按年绘制生物量。所以我需要用相同的时间值取 lon 和 lat 的平均值？这是我的代码。但是当我运行时，它给出了一个空的情节：

'''

library(ncdf4)
library(tidyverse)

our_nc_data <- nc_open("corr_eco3m_bs44_conversion_factor_v7_withDetritus_MEECE.nc")
print(our_nc_data)

lat <- ncvar_get(our_nc_data, "latitude")
lon <- ncvar_get(our_nc_data, "longitude")
time <- ncvar_get(our_nc_data, "time")

nt <- dim(time)

start_date <- as.Date("1980-01-01")
time_seq <- seq(start_date, by = "15 days", length.out = nt)

biomass_array <- ncvar_get(our_nc_data, "Zo")
fillvalue <- ncatt_get(our_nc_data, "Zo", "_FillValue")

biomass_array[biomass_array == fillvalue$value] <- NA

lonlattime <- as.matrix(expand.grid(lon, lat, time_seq))
head(lonlattime)
dim(lonlattime)

biomass_vec_long <- as.vector(biomass_array)
biomass_vec_long
length(biomass_vec_long)

biomass_obs <- data.frame(cbind(lonlattime, biomass_vec_long))
head(biomass_obs)

colnames(biomass_obs) <- c("Long", "Lat", "Date", "Biomass_Zo")
head(biomass_obs)

biomass_final <- na.omit(biomass_obs)
head(biomass_final)
dim(biomass_final)

biomass_final <- biomass_final[-c(1:2)]

glimpse(biomass_final)

biomass_final$Date <- as.Date(biomass_final$Date)
biomass_final$Biomass_Zo <- as.double(biomass_final$Biomass_Zo)


# Take the mean 
biomass_final <- biomass_final %>%
  group_by(Date) %>%
  summarize(Mean_biomass = mean(Biomass_Zo, na.rm = TRUE))

write.csv(as.data.frame(lswt_final), "Zo_biomass.csv", row.names=T)


# Plot the data using ggplot2
ggplot(biomass_final, aes(x = Date, y = Mean_biomass)) +
  geom_line(size = 0.5) +
  labs(x = "Date", y = "Biomass_Zo") +
  theme(axis.text.x = element_text(angle = 90, hjust = 1))

'''

Answer 1

我刚刚用您提供的

dput

试了一下，我得到了一个非空的情节。 我将

size = 

替换为

linewith =

，因为

size

已被弃用，并且我转换为对数刻度，因为您的

Mean_biomass

值范围如此之大：

ggplot(biomass_final, aes(x = Date, y = Mean_biomass)) +
  geom_line(linewidth = 0.5) +
  labs(x = "Date", y = "Biomass_Zo") +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) + 
  scale_y_log10()