Creating multiple plots from a data frame in R

Question

I am relatively new to R and have a dataset in .csv format that looks like this:

WCF Well    Constit  Date   Value   Unit    Filtered    Flag    Median  Min Max
299-E24-20_Chloroform_N 299-E24-20  Chloroform  12/6/2016   0.15    ug/L    N   J   0.145   0.14    0.19
299-E24-20_Chloroform_N 299-E24-20  Chloroform  3/14/2017   0.14    ug/L    N   J   0.145   0.14    0.19
299-E24-20_Chloroform_N 299-E24-20  Chloroform  6/15/2017   0.14    ug/L    N   J   0.145   0.14    0.19
299-E24-20_Chloroform_N 299-E24-20  Chloroform  9/20/2017   0.19    ug/L    N   J   0.145   0.14    0.19
299-E24-20_Sulfide_N    299-E24-20  Sulfide 12/6/2016   5800    ug/L    N   B   2200    2200    5800
299-E24-22_Sulfide_N    299-E24-22  Sulfide 12/6/2016   1470    ug/L    N   B   33  33  1470
299-E25-2_Sulfide_N 299-E25-2   Sulfide 11/1/2016   3380    ug/L    N   NA  33  33  3380
299-E25-2_Sulfide_N 299-E25-2   Sulfide 12/6/2016   1570    ug/L    N   B   33  33  3380
299-E24-20_Sulfide_N    299-E24-20  Sulfide 3/14/2017   2200    ug/L    N   UO  2200    2200    5800
299-E24-20_Sulfide_N    299-E24-20  Sulfide 6/15/2017   2200    ug/L    N   U   2200    2200    5800
299-E24-20_Sulfide_N    299-E24-20  Sulfide 9/20/2017   2200    ug/L    N   U   2200    2200    5800
299-E24-22_Sulfide_N    299-E24-22  Sulfide 3/13/2017   33  ug/L    N   U   33  33  1470
299-E24-22_Sulfide_N    299-E24-22  Sulfide 6/15/2017   33  ug/L    N   U   33  33  1470
299-E24-22_Sulfide_N    299-E24-22  Sulfide 9/18/2017   33  ug/L    N   U   33  33  1470
299-E25-2_Sulfide_N 299-E25-2   Sulfide 1/25/2017   1.00E+03    ug/L    N   U   33  33  3380
299-E25-2_Sulfide_N 299-E25-2   Sulfide 3/14/2017   33  ug/L    N   U   33  33  3380
299-E25-2_Sulfide_N 299-E25-2   Sulfide 4/19/2017   33  ug/L    N   U   33  33  3380
299-E25-2_Sulfide_N 299-E25-2   Sulfide 6/16/2017   33  ug/L    N   U   33  33  3380
299-E25-2_Sulfide_N 299-E25-2   Sulfide 9/15/2017   33  ug/L    N   U   33  33  3380

I have code that I have put together in an attempt to create multiple plots from the dataset and save them as .png's to a specified folder. Whenever I run the code, I don't get any errors but no plots appear to be generated because none are saved to the folder location. The code is listed below. Can anyone please help me find out why I'm not getting any plots?

#call required libraries

library(dplyr)
library(tidyr)
library(readr)
library(ggplot2)
library(magrittr)
library(stringi)
library(lubridate)
library(stats)

#load in datafiles

df <- read_csv ("C:/mypath/_dat.csv", col_names = TRUE)
df %>%
mutate(Date = mdy(Date))

# create graphing function

wcf.plot <- function(df){
  wcf_list <- unique(df$WCF)
  for( i in (wcf_list)){
    plots <- 
      ggplot(data=subset(df, df$WCF==wcf_list[i]), aes(Date, Value, group = WCF)) +
      geom_point(aes(color = Flag)) +
      ggtitle(paste(wcf_list[i])) +
      geom_abline(lm(data = df, Value~Date)) +
      xlab("Sample Date") +
      ylab("Conc ug/L or pCi/L")
      ggsave(plots, file=paste(plots,'C:/Projects/multiplotter/multiplotter/plots_png/', wcf_list[i], ".png",  sep='', scale=2))
      print(plots)
  }
}

I do get a warning when running the code indicating "8 failed to parse". Does that mean that eight columns of my data are not useable? Thanks!

Answer 1

something like this (data at the bottom of answer),

# setwd('C:/Projects/multiplotter/multiplotter/plots_png/')

for (var in unique(tbl$WCF)) {
ggplot(subset(tbl, WCF == var), aes(Date, Value)) +
      geom_point(aes(color = Flag)) +
      geom_smooth(method = "lm", se = FALSE) + 
      labs(x = "Sample Date", y = "Conc ug/L or pCi/L", title = paste0(var))
 ggsave(paste0(var,'.png'), width = 20, height = 20, units = "cm")
    }

cat('your plots where saved into;', getwd())
#> your plots where saved into; C:/Projects/multiplotter/multiplotter/plots_png/

See also this so answer. Plus, bonus plot using facet_grid() as it does give a a good sense of what the data in one plot,

ggplot(tbl, aes(Date, Value)) +
      geom_point(aes(color = Flag)) +
      geom_smooth(method = "lm", se = FALSE) + 
      labs(x = "Sample Date", y = "Conc ug/L or pCi/L") + facet_grid(. ~ WCF)

df <- structure(list(WCF = structure(c(1L, 1L, 1L, 1L, 2L, 3L, 4L, 
4L, 2L, 2L, 2L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L), .Label = c("299-E24-20_Chloroform_N", 
"299-E24-20_Sulfide_N", "299-E24-22_Sulfide_N", "299-E25-2_Sulfide_N"
), class = "factor"), Well = structure(c(1L, 1L, 1L, 1L, 1L, 
2L, 3L, 3L, 1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L), .Label = c("299-E24-20", 
"299-E24-22", "299-E25-2"), class = "factor"), Constit = structure(c(1L, 
1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L), .Label = c("Chloroform", "Sulfide"), class = "factor"), 
    Date = structure(c(3L, 5L, 7L, 11L, 3L, 3L, 2L, 3L, 5L, 7L, 
    11L, 4L, 7L, 10L, 1L, 5L, 6L, 8L, 9L), .Label = c("1/25/2017", 
    "11/1/2016", "12/6/2016", "3/13/2017", "3/14/2017", "4/19/2017", 
    "6/15/2017", "6/16/2017", "9/15/2017", "9/18/2017", "9/20/2017"
    ), class = "factor"), Value = c(0.15, 0.14, 0.14, 0.19, 5800, 
    1470, 3380, 1570, 2200, 2200, 2200, 33, 33, 33, 1000, 33, 
    33, 33, 33), Unit = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "ug/L", class = "factor"), 
    Filtered = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "N", class = "factor"), 
    Flag = structure(c(2L, 2L, 2L, 2L, 1L, 1L, NA, 1L, 4L, 3L, 
    3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("B", "J", 
    "U", "UO"), class = "factor"), Median = c(0.145, 0.145, 0.145, 
    0.145, 2200, 33, 33, 33, 2200, 2200, 2200, 33, 33, 33, 33, 
    33, 33, 33, 33), Min = c(0.14, 0.14, 0.14, 0.14, 2200, 33, 
    33, 33, 2200, 2200, 2200, 33, 33, 33, 33, 33, 33, 33, 33), 
    Max = c(0.19, 0.19, 0.19, 0.19, 5800, 1470, 3380, 3380, 5800, 
    5800, 5800, 1470, 1470, 1470, 3380, 3380, 3380, 3380, 3380
    )), .Names = c("WCF", "Well", "Constit", "Date", "Value", 
"Unit", "Filtered", "Flag", "Median", "Min", "Max"),
 class = "data.frame", row.names = c(NA, -19L))

tbl <- df %>% mutate(Date = mdy(Date)) %>% arrange(WCF) %>% group_by(WCF) %>% as_tibble()