The loadflex R package implements several of the most common methods
for modeling and predicting watershed solute fluxes and concentrations,
including interpolation and regression models, period-weighted
averaging, and the composite method. loadflex integrates seamlessly
with the USGS’s
rloadest package
and with native R regression models. It offers a uniform interface for
any model type, with which you can quickly fit models, generate
predictions, and aggregate to monthly or annual values.
To see the recommended citation for this package, please run
citation('loadflex') at the R prompt.
citation('loadflex')
## To cite package 'loadflex' in publications use:
##
## Appling, A. P., M. C. Leon, and W. H. McDowell. 2015. Reducing bias
## and quantifying uncertainty in watershed flux estimates: the R
## package loadflex. Ecosphere 6(12):269.
## https://doi.org/10.1890/ES14-00517.1
##
## A BibTeX entry for LaTeX users is
##
## @Article{,
## title = {Reducing bias and quantifying uncertainty in watershed flux estimates: the R package loadflex},
## author = {Alison P. Appling and Miguel C. Leon and William H. McDowell},
## year = {2015},
## journal = {Ecosphere},
## volume = {6},
## number = {12},
## pages = {art269},
## doi = {10.1890/ES14-00517.1},
## url = {http://www.esajournals.org/doi/full/10.1890/ES14-00517.1},
## }To install the loadflex package, use the remotes package as follows.
You will need a compiler to install smwrStats, smwrQW, and
rloadest – for Windows, see
https://cran.r-project.org/bin/windows/Rtools/rtools43/rtools.html.
For Mac, see https://mac.r-project.org/tools/.
# install.packages("remotes") # run if needed
remotes::install_gitlab("water/analysis-tools/smwrData", host = "code.usgs.gov")
remotes::install_gitlab("water/analysis-tools/smwrBase", host = "code.usgs.gov")
remotes::install_gitlab("water/analysis-tools/smwrGraphs", host = "code.usgs.gov")
remotes::install_gitlab("water/analysis-tools/smwrStats", host = "code.usgs.gov") # needs compilation
remotes::install_gitlab("water/analysis-tools/smwrQW", host = "code.usgs.gov") # needs compilation
remotes::install_github("USGS-R/rloadest") # needs compilation
remotes::install_github("appling/unitted")
remotes::install_github("DOI-USGS/EGRET")
remotes::install_github("DOI-USGS/loadflex", build_vignettes=TRUE)Credentials, if needed: loadflex and its dependencies are all on
public websites, so you shouldn’t need to create any Personal Access
Tokens (PATs), but sometimes it seems to help anyway, depending on your
network and account settings. If you encounter errors in accessing
code.usgs.gov or github.com in any of the above remotes:: commands: *
to use remotes::install_gitlab() you may need to create and store a
GitLab
PAT for
the USGS GitLab instance at code.usgs.gov
(https://code.usgs.gov/-/user_settings/personal_access_tokens). * to
use remotes::install_github() you may need to create and store a
GitHub
PAT
for github.com (https://github.com/settings/personal-access-tokens).
The currently recommended
method
for storing your PATs within R is to call gitcreds::gitcreds_set() and
enter the PATs you established on the GitLab and GitHub websites.
# install.packages("gitcreds") # run if needed
gitcreds::gitcreds_set(url = 'https://code.usgs.gov') # enter your code.usgs.gov GITLAB_PAT value (begins with `glpat_`) at the interactive prompt
gitcreds::gitcreds_set() # enter your GITHUB_PAT value (begins with `ghp_`) at the interactive promptAlso please see the installation FAQ on the wiki (https://github.com/DOI-USGS/loadflex/wiki/Installation-FAQ) if you run into trouble.
To get started, load the package with library(loadflex) and type
?loadflex or vignette('intro_to_loadflex', package = 'loadflex').
The vignette is also viewable at
https://doi-usgs.github.io/loadflex/articles/intro_to_loadflex.html.
Project funding has ended and our maintenance time is limited, but we do attempt to provide bug fixes and lightweight support as we are able. Submit questions or suggestions to https://github.com/DOI-USGS/loadflex/issues.
We want to encourage a warm, welcoming, and safe environment for contributing to this project. See CODE_OF_CONDUCT.md for more information.
For technical details on how to contribute, see CONTRIBUTING.md
loadflex was created 2013-2015 by Alison
Appling and Miguel
Leon with the support of Bill
McDowell and the McDowell
lab at the University of New
Hampshire. Funding for the project was provided by the National Science
Foundation, USDA National Institute of Food and Agriculture, and the NH
Agricultural Experiment Station. Funding for the example dataset from
the Lamprey River was provied by the EPA, NH Water Resources Research
Center, NH Agricultural Experiment Station, NH Sea Grant, USGS, and NSF.
Additional development and maintenance in 2016-2017 was done by Alison Appling, Lindsay Platt, and David Watkins with support from the USGS National Water Quality Program and the USGS Office of Water Information.
The following version of R and package dependencies were used most recently to pass the embedded tests within this package. There is no guarantee of reproducible results using future versions of R or updated versions of package dependencies; however, we aim to test and update future modeling environments.
## ─ Session info ───────────────────────────────────────────────────────────────
## setting value
## version R version 4.5.2 (2025-10-31)
## os macOS Tahoe 26.7.1
## system aarch64, darwin20
## ui X11
## language (EN)
## collate C.UTF-8
## ctype C.UTF-8
## tz America/New_York
## date 2026-10-13
##
## ─ Packages ───────────────────────────────────────────────────────────────────
## package * version date (UTC) lib source
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## EGRET 3.0.12 2026-10-12 [2] Github (DOI-USGS/EGRET@b5eb22c)
## evaluate 1.0.5 2025-08-27 [2] CRAN (R 4.5.0)
## farver 2.1.2 2024-05-13 [2] CRAN (R 4.5.0)
## fastmap 1.2.0 2024-05-15 [2] CRAN (R 4.5.0)
## Formula 1.2-6 2026-08-03 [2] CRAN (R 4.5.2)
## generics 0.1.4 2025-05-09 [2] CRAN (R 4.5.0)
## ggplot2 4.0.3 2026-04-22 [2] CRAN (R 4.5.2)
## glue 1.8.1 2026-04-17 [2] CRAN (R 4.5.2)
## gtable 0.3.6 2024-10-25 [2] CRAN (R 4.5.0)
## htmltools 0.5.9 2025-12-04 [2] CRAN (R 4.5.2)
## KernSmooth 2.23-27 2026-08-12 [2] CRAN (R 4.5.2)
## knitr 1.52 2026-09-06 [2] CRAN (R 4.5.2)
## lattice 0.23-1 2026-08-12 [2] CRAN (R 4.5.2)
## lazyeval 0.2.3 2026-04-04 [2] CRAN (R 4.5.2)
## leaps 3.2 2024-06-10 [2] CRAN (R 4.5.0)
## libcoin 1.0-13 2026-06-04 [2] CRAN (R 4.5.2)
## lifecycle 1.0.5 2026-01-08 [2] CRAN (R 4.5.2)
## loadflex * 1.9.3 2026-10-13 [1] local
## lubridate * 1.9.5 2026-02-04 [2] CRAN (R 4.5.2)
## magrittr 2.0.5 2026-04-04 [2] CRAN (R 4.5.2)
## MASS 7.3-66 2026-07-15 [2] CRAN (R 4.5.2)
## Matrix 1.7-6 2026-07-25 [2] CRAN (R 4.5.2)
## matrixStats 1.5.0 2025-01-07 [2] CRAN (R 4.5.0)
## memoise 2.0.1 2021-11-26 [2] CRAN (R 4.5.0)
## modeltools 0.2-25 2026-09-30 [2] CRAN (R 4.5.2)
## multcomp 1.4-32 2026-08-21 [2] CRAN (R 4.5.2)
## mvtnorm 1.4-2 2026-07-12 [2] CRAN (R 4.5.2)
## NADA 1.6-1.2 2025-08-29 [2] CRAN (R 4.5.0)
## nlme 3.1-171 2026-09-01 [2] CRAN (R 4.5.2)
## otel 0.2.0 2025-08-29 [2] CRAN (R 4.5.0)
## pillar 1.11.1 2025-09-17 [2] CRAN (R 4.5.0)
## pkgconfig 2.0.3 2019-09-22 [2] CRAN (R 4.5.0)
## proxy 0.4-29 2025-12-29 [2] CRAN (R 4.5.2)
## R6 2.6.1 2025-02-15 [2] CRAN (R 4.5.0)
## randtests 1.0.2 2024-04-23 [2] CRAN (R 4.5.0)
## RColorBrewer 1.1-3 2022-04-03 [2] CRAN (R 4.5.0)
## Rcpp 1.1.2 2026-07-05 [2] CRAN (R 4.5.2)
## rlang 1.3.0 2026-07-05 [2] CRAN (R 4.5.2)
## rloadest * 0.4.5 2026-10-12 [2] Github (USGS-R/rloadest@8a8119f)
## rmarkdown 2.32 2026-09-01 [2] CRAN (R 4.5.2)
## S7 0.2.2 2026-04-22 [2] CRAN (R 4.5.2)
## sandwich 3.1-3 2026-08-03 [2] CRAN (R 4.5.2)
## scales 1.4.0 2025-04-24 [2] CRAN (R 4.5.0)
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## sf 1.1-3 2026-09-11 [2] CRAN (R 4.5.2)
## smwrBase * 1.1.5 2026-10-12 [2] gitlab (water/analysis-tools/smwrBase@8037379)
## smwrGraphs * 1.1.4.9000 2026-02-13 [2] gitlab (water/analysis-tools/smwrGraphs@e494d6f)
## smwrQW * 0.7.14 2026-02-13 [2] gitlab (water/analysis-tools/smwrQW@b6211ad)
## smwrStats * 0.7.6 2026-10-12 [2] gitlab (water/analysis-tools/smwrStats@7fa1862)
## sp 2.2-4 2026-10-11 [2] CRAN (R 4.5.2)
## survival 3.8-12 2026-09-09 [2] CRAN (R 4.5.2)
## TH.data 1.1-5 2025-11-17 [2] CRAN (R 4.5.2)
## tibble 3.3.1 2026-01-11 [2] CRAN (R 4.5.2)
## tidyselect 1.2.1 2024-03-11 [2] CRAN (R 4.5.0)
## timechange 0.4.0 2026-01-29 [2] CRAN (R 4.5.2)
## truncnorm 1.0-9 2023-03-20 [2] CRAN (R 4.5.0)
## units 1.0-1 2026-03-11 [2] CRAN (R 4.5.2)
## unitted 0.2.9 2026-10-12 [2] Github (appling/unitted@0585684)
## vctrs 0.7.3 2026-04-11 [2] CRAN (R 4.5.2)
## xfun 0.61 2026-09-16 [2] CRAN (R 4.5.2)
## XML 3.99-0.25 2026-09-27 [2] CRAN (R 4.5.2)
## yaml 2.3.12 2025-12-10 [2] CRAN (R 4.5.2)
## zCompositions 1.6.2 2026-06-23 [2] CRAN (R 4.5.2)
## zoo 1.9-1 2026-09-25 [2] CRAN (R 4.5.2)
##
## * ── Packages attached to the search path.
##
## ──────────────────────────────────────────────────────────────────────────────
This software is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The software has not received final approval by the U.S. Geological Survey (USGS). No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. The software is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the software.