Demos

OTM is written in Java, and includes connections to Matlab and Python. This is done via OTM’s Java API. The Matlab and Python interfaces are included with otm-tools. All of the methods in the Java API are accessible from Matlab and Python, so the Java documentation is valid for all three languages. The Matlab and Python interfaces provide additional useful methods in the OTMWrapper class.

A few simple examples are provided below.

Load a scenario

Java (source)

try {
    core.OTM otm = new core.OTM("line_ctm.xml", true);
    System.out.println(otm==null ? "Failure" : "Success");
} catch (Exception e) {
    System.err.print(e.getMessage());
    fail();
}

Python (source)

from OTMWrapper import OTMWrapper
otm = OTMWrapper("../configs/line.xml")
del otm

Matlab (source)

import api.OTM
otm = OTMWrapper("../configs/line.xml");

Run a complete simulation

Java (source)

try {
    // load the scenario
    core.OTM otm = new core.OTM("line_ctm.xml", true);

    // request 10-second sampling of all link flows and densities
    float outdt = 10f;  // sampling time in seconds
    Set<Long> link_ids = otm.scenario.network.link_ids();  // request all link ids
    otm.output.request_links_flow(null,null,null,link_ids,outdt);
    otm.output.request_links_veh(null,null,null,link_ids,outdt);

    // run the simulation for 200 seconds
    otm.run(0,200f);

    // plot the output by iterating through the requested output data and
    // calling the 'plot_for_links' method.
    otm.plot_outputs("temp");

} catch (OTMException e) {
    System.err.print(e.getMessage());
    fail();
}

Python (source)

from OTMWrapper import OTMWrapper
from matplotlib import pyplot as plt 

# open the api
otm = OTMWrapper('../configs/line.xml')

# Plot the network
otm.show_network()

# run a simulation
otm.run_simple(start_time=0,duration=1500,output_dt=10)

# extract the state trajectory
Y = otm.get_state_trajectory()

# plot the state trajectory
fig = plt.figure()
plt.subplot(311)
plt.plot(Y['time'],Y['vehs'].T) 
plt.ylabel("vehicles") 
plt.title("OTM simulation result") 
plt.subplot(312)
plt.plot(Y['time'],Y['flows_vph'].T)
plt.ylabel("flow [vph]") 
plt.subplot(313)
plt.plot(Y['time'],Y['speed_kph'].T)
plt.ylabel("speed [kph]") 
plt.legend(['link 1','link 2','link 3'])
plt.xlabel("time [sec]") 
plt.draw()

plt.show()

# always end by deleting the wrapper
del otm

Matlab (source)

import api.OTM

% load the configuration file into an OTMWrapper object
otm = OTMWrapper("../configs/line.xml");

% run a simulation
start_time = 0;
duration = 1000;
request_links = [1 2 3];
outdt = 10;
otm.run_simple(start_time,duration,request_links,request_dt)

% extract the state trajectory
Y = otm.get_state_trajectory;

% plot the state trajectory
figure
subplot(311)
plot(Y.time,Y.vehs)
subplot(312)
plot(Y.time(2:end),Y.flows_vph)
subplot(313)
plot(Y.time(2:end),Y.speed_kph)

Run a scenario step-by-step

Java (source)

try {
    float start_time = 0f;
    float duration = 3600f;
    float advance_time = 300f;

    // load the scenario
    core.OTM otm = new core.OTM("line_ctm.xml", true);

    // initialize (prepare/rewind the simulation)
    otm.initialize(start_time);

    // run step-by-step using the 'advance' method
    float time = start_time;
    float end_time = start_time + duration;

    while (time < end_time) {
        System.out.println(time);
        otm.advance(advance_time);

        // Insert your code here -----

        time += advance_time;
    }

} catch (OTMException e) {
    System.err.print(e.getMessage());
    fail();
}

Python (source)

from OTMWrapper import OTMWrapper

start_time = 0.
duration = 3600.
advance_time = 300.

# load the configuration file
otm = OTMWrapper('../configs/line.xml')

# initialize (prepare/rewind the simulation)
otm.initialize(start_time)

# run step-by-step using the 'advance' method
time = start_time
end_time = start_time + duration

while(time<end_time):
  otm.advance(advance_time)

  # Insert your code here -----
  print(otm.otm.get_current_time())

  time += advance_time;

# always end by deleting the wrapper
del otm

Matlab (source)

import api.OTM

start_time = 0;
duration = 3600;
advance_time = 300;

% load the configuration file into an OTMWrapper object
otm = OTMWrapper('../configs/line.xml');

% initialize (prepare/rewind the simulation)
otm.initialize(start_time);

% run step-by-step using the 'advance' method
time = start_time;
end_time = start_time+duration;

while(time<end_time)
  otm.advance(advance_time);

  % Insert your code here -----
  disp(otm.api.get_current_time())

  time = time + advance_time;
end

Write a controller plugin

Coming soon…

Write a model plugin

Coming soon…