MIDASFlow-R is the R interface to the Memory-Efficient I/O-Improved Drainage Analysis System (MIDAS). MIDAS needs to be installed separately in PATH.

• MIDAS: Core C library and excutables (required for all Python, R, and QGIS interfaces)
• r.flowaccumulation: GRASS addon for MEFA
• r.hydrobasin: GRASS addon for MESHED
• r.lfp: GRASS addon for MELFP
• r.upflowlength: GRASS addon for MEUFL
• MIDASFlow: Python package
• MIDAS-QGIS: QGIS plugin

install.packages("remotes")
remotes::install_git("git@github.com:HuidaeCho/midasflow-r.git")
library(midasflow)

meshed("fdr.tif", "outlets.shp", "cat", "wsheds.tif")

• MEFA (Flow Accumulation): Huidae Cho, July 2023. Memory-Efficient Flow Accumulation Using a Look-Around Approach and Its OpenMP Parallelization. Environmental Modelling & Software 167, 105771. doi:10.1016/j.envsoft.2023.105771. Author's Version.
• MESHED (Watershed Delineation): Huidae Cho, January 2025. Avoid Backtracking and Burn Your Inputs: CONUS-Scale Watershed Delineation Using OpenMP. Environmental Modelling & Software 183, 106244. doi:10.1016/j.envsoft.2024.106244. Author's Version.
• MELFP (Longest Flow Path): Huidae Cho, September 2025. Loop Then Task: Hybridizing OpenMP Parallelism to Improve Load Balancing and Memory Efficiency in Continental-Scale Longest Flow Path Computation. Environmental Modelling & Software 193, 106630. doi:10.1016/j.envsoft.2025.106630. Author's Version.
• MEUFL (Upstream Flow Length): Huidae Cho, September 2026. Flow in Float: Memory-Efficient Upstream Flow Length Parallel Computation Using an IEEE-754-Based Union Encoding. Environmental Modelling & Software 204, 107045. doi:10.1016/j.envsoft.2026.107045. Author's Version.

N(.N)*[{a|b|rc}N][.postN][.devN]

• PEP 440
• {a|b|rc|.dev}N towards and .postN away from the release
• Not fully compatible with semantic versioning
• Not using build numbers marching away from or towards a release, but check this interesting comment.

Copyright (C) 2025 Huidae Cho

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.