Overview

fluxtools is an R package that provides an interactive Shiny‐based QA/QC environment to explore or remove data in the AmeriFlux BASE (or Fluxnet) format. In just a few clicks, you can:

1. Upload eddy covariance data in a .csv format (AmeriFlux standard naming and timestamp conventions; up to ~1 GB)
2. Visualize any numeric variable against time (default: TIMESTAMP_START) or against another variable
3. Detect outliers with the ±σ slider (residuals from a simple linear fit) and stage them for removal
4. Manually flag points using box/lasso selection, time ranges, or custom min/max thresholds
5. Overlay or compare: Plot multiple Y variables in the same dataset, or upload a second dataset (Dataset B) for side-by-side comparison with Dataset A
6. Add smoothers (LOESS) with adjustable span and optional 95% CI; optionally show only smoothed line(s)
7. Apply PRM (Physical Range Module) to automatically replace values outside published physical bounds
8. Generate reproducible code: fluxtools builds dplyr code that sets flagged values to NA_real_. Copy current or accumulated snippets directly
9. Download results: export a ZIP with cleaned CSV(s), replay scripts, and (if PRM applied) summary/audit files

This vignette shows you how to install, launch, and use the main Shiny app—run_fluxtools()—and walks through a typical workflow.

Installation

You can install fluxtools from CRAN, or directly from GitHub:

# Install from CRAN 
install.packages("fluxtools")

# Install from GitHub
library(devtools) 
devtools::install_github("kesondrakey/fluxtools")

Launching the Shiny App

Load fluxtools and launch the QA/QC application:

library(fluxtools)

# Run the app
run_fluxtools()

Example workflow

• Upload: Select your AmeriFlux-style CSV (e.g., US_VT1_HH_202401010000_202501010000.csv). Files can be up to 1GB (larger file sizes might be harder on the Shiny interface)

• Choose Year(s): By default “all” is selected, but you can subset to specific years

• Choose variables: TIMESTAMP_START is on the x-axis by default. Change the y-axis to your variable of interest (e.g., FC_1_1_1). The generated R code focuses on removing the y-axis variable

• Compare Two Datasets Upload a second dataset (Dataset B) to compare against your primary upload (Dataset A).

• ⚠️ Note: Flagging and removals only apply to Dataset A

• You can assign custom labels for each dataset, which appear in the legend

• Choose custom colors per dataset

• All advanced options (smoothers, lines vs. points, opacity, etc.) work in comparison mode, except global themes and single-variable color overrides (which apply to Dataset A only)

• Plot Multiple Variables (Overlay) Enable Plot multiple variables to overlay several Y variables from the same dataset in one plot

• Select variables in the Overlay variables menu.

• Use Include current Y-variable if you want the currently selected variable included automatically

• Colors are assigned from the active palette; you can override them manually in Advanced Options

• Advanced Options (Flag Style & Markers)

• Switch between scatter and line plots

• Adjust opacity and line width

• In single-variable mode, markers can be hollow circles for better visibility of flagged rings

• Smoother Overlay Add a LOESS smoother to any plot:

• Adjustable span parameter to control curve smoothness

• Option to display a 95% confidence interval

• Toggle Show only smoothed line(s) to hide base scatter/lines and keep just the LOESS curves

• Color Options

• For single-variable or overlay mode, colors follow the chosen palette (Okabe–Ito, Tableau10, viridis, etc.) or manual overrides

• For dataset comparison, colors are set separately under the Compare two datasets menu

• Time Subsetting Subset your dataset by year, month(s), day(s), or time of day

• Example: Select 06:00–18:00 to restrict analysis to daytime values

• Icons update dynamically: a ☀️ sun for daytime, 🌙 moon for nighttime

• Select data: Use the box or lasso to select points. This populates the “Current” code box with something like:

   df <- df %>%
     mutate(
       FC_1_1_1 = case_when(
         TIMESTAMP_START == '202401261830' ~ NA_real_,
         TIMESTAMP_START == '202401270530' ~ NA_real_,
         …
         TRUE ~ FC_1_1_1
       )
     )

• Flag data and Accumulate code: With points still selected, click “Flag data.” Selected points turn orange, and code is appended to the “Accumulated” box, allowing multiple selections per session.

• Unflag data: Use the box or lasso to de-select points and remove from the Accumulated code box.

• Clear Selection: To reset all selections from the current y-variable, click “Clear Selection” to reset the current view.

• Switch variables: Change y to any other variable (e.g., SWC_1_1_1) and select more points. Click “Flag data” Code for both variables to appear:

   df <- df %>%
     mutate(
       FC_1_1_1 = case_when(
         TIMESTAMP_START == '202401261830' ~ NA_real_,
         TIMESTAMP_START == '202401270530' ~ NA_real_,
         …
         TRUE ~ FC_1_1_1
       )
     )

   df <- df %>%
     mutate(
       SWC_1_1_1 = case_when(
         TIMESTAMP_START == '202403261130' ~ NA_real_,
         TIMESTAMP_START == '202403270800' ~ NA_real_,
         …
         TRUE ~ SWC_1_1_1
       )
     )

• Compare variables: Change to variables you would like to compare (e.g., change y to TA_1_1_1 and x to T_SONIC_1_1_1). The app computes an R² via simple linear regression. The top R² is based on points before removals, and once data is selected, a second R² will pop up - calculating the linear regression assuming the selected points have been removed

• Highlight outliers: Use the slider to select ±σ residuals. Click “Select all ±σ outliers” to append them to the Accumulated code. Click “Clear ±σ outliers” to deselect and remove from the code box

• Copy all: Click the Copy Icon to the right of the current or accumulated code box and paste into your own R script for documentation

• Apply Removals: Click “Apply Removals” to remove each selected data points, from the current y-variable, to replace points with NA in a new .csv (raw data is unaffected), available using ‘export cleaned data’ and remove these values from view

• Reload original data: Make a mistake or want a fresh start? Click Reload original data to reload the .csv from above to start over

• Export cleaned data: Download a ZIP containing:

• A cleaned CSV (with applied NAs)

• An R script that reproduces your removals

• Optional PRM summary when used (see below)

• Physical Boundary Module (PRM) function: The Physical Range Module (PRM) removes out-of-range values to NA based on similar variables using patterns like ^SWC($|_) or ^P($|_).
  Columns containing "QC" are skipped by default. No columns are removed.

Source of ranges: AmeriFlux Technical Documents, Table A1 (Physical Range Module).

# tiny demo dataset with a few out-of-range values
set.seed(1)
df <- tibble::tibble(
  TIMESTAMP_START = seq.POSIXt(as.POSIXct("2024-01-01", tz = "UTC"),
                               length.out = 10, by = "30 min"),
  SWC_1_1_1 = c(10, 20, 150, NA, 0.5, 99, 101, 50, 80, -3),  # bad: 150, 101, -3; 0.5 triggers SWC unit note
  P         = c(0, 10, 60, NA, 51, 3, 0, 5, 100, -1),        # bad: 60, 51, 100, -1
  RH_1_1_1  = c(10, 110, 50, NA, 0, 100, -5, 101, 75, 30),   # bad: 110, -5, 101
  SWC_QC    = sample(0:2, 10, replace = TRUE)                # QC col should be ignored
)

# To see the Physical Boundary Module (PRM) rules:
get_prm_rules()

#Apply filter to all relevant variables
res <- apply_prm(df)

# PRM summary (counts and % replaced per column)
res$summary

# Only set range for SWC 
df_filtered_swc <- apply_prm(df, include = "SWC")

# Only set range for SWC + P 
df_filtered_swc_P <- apply_prm(df, include = c("SWC", "P"))