epanetReader is an R package for reading water network simulation data in Epanet's .inp and .rpt formats into R. Some basic summary information and plots are also provided.
Epanet is a highly popular tool for water network simulation. It can difficult to access network information for subsequent analysis and visualization. This is a real strength of R however, and there many tools already existing in R to support analysis and visualization.
Reading an .inp or .rpt file creates an s3 object which can be used with the usual generic methods.
The package is also useful in conjunction with the ggplot2 and animation packages.
So far the package is only available on GitHub. The plan is to eventually submit to CRAN.
install.packages("devtools") devtools::install_github("bradleyjeck/epanetReader")
Read network information from an .inp file with a similar syntax as the popular read.table or read.csv functions.
>n1 <- read.inp("Net1.inp") Retrieve summary information about the network.
>summary(n1)
$Title
[1] "EPANET Example Network 1"
[2] "A simple example of modeling chlorine decay. Both bulk and"
[3] "wall reactions are included."
$entryCounts
Number
Junctions 9
Tanks 1
Reservoirs 1
Pipes 12
Pumps 1
Coordinates 11
attr(,"class")
[1] "summary.epanet.inp"A basic network plot is also available
>plot(n1)
The read.inp function returns an object with structure similar to the .inp file itself. A section in the .inp file corresponds to a named entry in the list. These entries are accessed using the $ syntax of R.
> names(n1)
[1] "Title" "Junctions" "Tanks" "Reservoirs" "Pipes"
[6] "Pumps" "Valves" "Patterns" "Curves" "Energy"
[11] "Times" "Options" "Coordinates"Sections of the .inp file are stored as a data.frame or character vector. For example, the junction table is stored as a data.frame and retrieved as follows. In this case patterns were not specified in the junction table and so are marked NA.
> n1$Junctions
ID Elevation Demand Pattern
1 10 710 0 NA
2 11 710 150 NA
3 12 700 150 NA
4 13 695 100 NA
5 21 700 150 NA
6 22 695 200 NA
7 23 690 150 NA
8 31 700 100 NA
9 32 710 100 NAA summary of the junction table shows that Net1.inp has nine junctions with elevations ranging from 690 to 710 and demands ranging from 0 to 200. Note that the node ID is stored as a character rather than an integer or factor.
> summary(n1$Junctions)
ID Elevation Demand Pattern
Length:9 Min. :690.0 Min. : 0.0 Mode:logical
Class :character 1st Qu.:695.0 1st Qu.:100.0 NA's:9
Mode :character Median :700.0 Median :150.0
Mean :701.1 Mean :122.2
3rd Qu.:710.0 3rd Qu.:150.0
Max. :710.0 Max. :200.0 Results of the network simulation specified in Net.inp may be stored in Net1.rpt by running Epanet from the command line. Note that the report section of the .inp file should contain the following lines in order to generate output readable by this package.
[REPORT]
Page 0
Links All
Nodes All
On windows, calling the epanet executable epanet2d runs the simulation.
>epanet2d Net1.inp Net1.rpt
... EPANET Version 2.0
o Retrieving network data
o Computing hydraulics
o Computing water quality
o Writing output report to Net1.rpt
... EPANET completed.
The .rpt file generated by Epanet may be read into R using read.rpt(). The simulation is summarized over junctions, tanks and pipes.
>n1r <- read.rpt("Net1.rpt")
>summary(n1r)
Contains node results for 25 time steps
Summary of Junction Results:
Demand Pressure Chlorine
Min. : 0.0 Min. :106.8 Min. :0.1500
1st Qu.: 80.0 1st Qu.:116.1 1st Qu.:0.3500
Median :120.0 Median :119.8 Median :0.5100
Mean :122.2 Mean :119.6 Mean :0.5434
3rd Qu.:160.0 3rd Qu.:123.0 3rd Qu.:0.7400
Max. :320.0 Max. :133.9 Max. :1.0000
Summary of Tank Results:
Demand Pressure Chlorine
Min. :-1100.000 Min. :48.22 Min. :0.590
1st Qu.: -660.000 1st Qu.:52.00 1st Qu.:0.660
Median : 258.000 Median :55.52 Median :0.750
Mean : -5.741 Mean :54.86 Mean :0.764
3rd Qu.: 505.380 3rd Qu.:57.54 3rd Qu.:0.850
Max. : 1029.420 Max. :60.04 Max. :1.000
Contains link results for 25 time steps
Summary of Pipe Results:
Flow Velocity Headloss
Min. :-1029.42 Min. :0.0000 Min. :0.000
1st Qu.: 41.37 1st Qu.:0.3475 1st Qu.:0.110
Median : 113.08 Median :0.5700 Median :0.300
Mean : 245.35 Mean :0.8070 Mean :0.644
3rd Qu.: 237.23 3rd Qu.:1.0075 3rd Qu.:0.755
Max. : 1909.42 Max. :2.7300 Max. :3.210 The default plot of simulation results is a map for time period 00:00:00. Note that the object created from the .inp file is a required argument to make the plot.
plot( n1r, n1)
In contrast to the treatment of .inp files described above, data from .rpt files is stored using a slightly different structure than the .rpt file. The function returns an object (list) with a data.frame for node results and data.frame for link results. These two data frames contain results from all the time periods. This storage choice was made to facilitate time series plots.
Entries in the epanet.rpt object (list) created by read.rpt() are found using the names() function.
> names(n1r)
[1] "nodeResults" "linkResults"Results for a chosen time period can be retrieved using the subset function.
> subset(n1r$nodeResults, Timestamp == "0:00:00")
Node Demand Head Pressure Chlorine note Timestamp timeInSeconds nodeType
1 10 0.00 1004.35 127.54 0.5 0:00:00 0 Junction
2 11 150.00 985.23 119.26 0.5 0:00:00 0 Junction
3 12 150.00 970.07 117.02 0.5 0:00:00 0 Junction
4 13 100.00 968.87 118.67 0.5 0:00:00 0 Junction
5 21 150.00 971.55 117.66 0.5 0:00:00 0 Junction
6 22 200.00 969.08 118.76 0.5 0:00:00 0 Junction
7 23 150.00 968.65 120.74 0.5 0:00:00 0 Junction
8 31 100.00 967.39 115.86 0.5 0:00:00 0 Junction
9 32 100.00 965.69 110.79 0.5 0:00:00 0 Junction
10 9 -1866.18 800.00 0.00 1.0 Reservoir 0:00:00 0 Reservoir
11 2 766.18 970.00 52.00 1.0 Tank 0:00:00 0 TankA comparison with the corresponding entry of the .rpt file, shown below for reference, shows that four columns have been added to the table. These pieces of extra info make visualizing the results easier.
Node Results at 0:00:00 hrs:
--------------------------------------------------------
Demand Head Pressure Chlorine
Node gpm ft psi mg/L
--------------------------------------------------------
10 0.00 1004.35 127.54 0.50
11 150.00 985.23 119.26 0.50
12 150.00 970.07 117.02 0.50
13 100.00 968.87 118.67 0.50
21 150.00 971.55 117.66 0.50
22 200.00 969.08 118.76 0.50
23 150.00 968.65 120.74 0.50
31 100.00 967.39 115.86 0.50
32 100.00 965.69 110.79 0.50
9 -1866.18 800.00 0.00 1.00 Reservoir
2 766.18 970.00 52.00 1.00 Tank
Rossman, L. A. (2000) Epanet 2 users manual. US EPA, Cincinnati, Ohio.