draw_ldc: Draw a load duration curve
In TxWRI/ldc: Calculate and Plot Pollutant Load Duration Curves

Description Usage Arguments Value Examples

View source: R/draw_ldc.R

Creates a load duration curve visualization from the outputs of calc_ldc and summ_ldc as a ggplot object.

draw_ldc(
  .tbl_calc,
  .tbl_summ,
  y_lab = NULL,
  ldc_legend_name = "Allowable Load at State Water Quality Standard",
  measurement_name = "Measurement Value",
  measurement_shape = 21,
  measurement_color = "dodgerblue",
  measurement_alpha = 1,
  summary_name = "Summarized Measured Load",
  summary_stat_shape = 12,
  summary_stat_color = "red",
  label_nudge_y = 0,
  label_font_family = "Arial",
  label_font_size = 3,
  label_break = TRUE
)

`.tbl_calc`	data frame object created by `calc_ldc`
`.tbl_summ`	data frame object created by `summ_ldc`
`y_lab`	optional string for y-axis label name, will be appended with units automatically. default is NULL.
`ldc_legend_name`	string, provides the name used for the allowable pollutant load line in the legend. required.
`measurement_name`	string, provides the name used for measured load values in the legend. required.
`measurement_shape`	aesthetic value passed to the layer plotting measured load values. defaults to `21`.
`measurement_color`	aesthetic value passed to the layer plotting measured load values. defaults to `"dodgerblue"`.
`measurement_alpha`	aesthetic value passed to the layer plotting measured load values. defaults to `1`.
`summary_name`	string, provides the name used for summary statistic values in the legend. required.
`summary_stat_shape`	aesthetic value passed to the layer plotting summary statistic values. defaults to `12`.
`summary_stat_color`	aesthetic value passed to the layer plotting summary statistic values. defaults to `"red"`.
`label_nudge_y`	numeric value to vertically nudge flow category labels. If a log10 transformed scale is being used, a log value is probably appropriate for example `log10(1000)`.
`label_font_family`	string specifying font family to use in flow category labels.
`label_font_size`	numeric value specifying font size to use in flow category labels.
`label_break`	logical, add line breaks to flow category labels. Labels will break at spaces.

ggplot object

# Basic example using built in Tres Palacios data
library(dplyr)
library(units)
library(ggplot2)
# Format data
install_unit("cfu")
df <- as_tibble(tres_palacios) %>%
        ## filter data so this run quicker
        filter(!is.na(Indicator_Bacteria)) %>%
        ## flow must have units, here is is in cfs
        mutate(Flow = set_units(Flow, "ft^3/s")) %>%
        ## pollutant concentration must have units
        mutate(Indicator_Bacteria = set_units(Indicator_Bacteria, "cfu/100mL"))
# Calculate LDC

## specify the allowable concentration
allowable_concentration <- 126
## set the units
units(allowable_concentration) <- "cfu/100mL"
df_ldc <- calc_ldc(df,
                   Q = Flow,
                   C = Indicator_Bacteria,
                   allowable_concentration = allowable_concentration)

# Summarize LDC
df_sum <- summ_ldc(df_ldc,
                   Q = Flow,
                   C = Indicator_Bacteria,
                   Exceedance = P_Exceedance,
                   groups = Flow_Category,
                   method = "geomean")

# Create ggplot object
draw_ldc(df_ldc,
         df_sum,
         y_lab = expression(paste(italic("E. coli"))),
         label_nudge_y = log10(1000)) +
         scale_y_log10() +
         theme(legend.title = element_blank(),
               legend.direction = "vertical",
               legend.position = "bottom")

## cleanup
remove_unit("cfu")