add MAX_TIME_BUDGET to accessibility evaluation

- to avoid potential extremely long row/calulation
- remove walk from settings.yml in Lima_Network

Author: jdlph

README.md

@@ -1,6 +1,6 @@
 # Path4GMNS
 
-Path4GMNS is an open-source, cross-platform, lightweight, and fast Python path engine for networks encoded in [GMNS](https://github.com/zephyr-data-specs/GMNS). Besides finding the static and time-dependent shortest path for simple analyses, its main functionality is to provide an efficient and flexible framework for column(path)-based modeling and applications in transportations (e.g., activity-based demand modeling). Path4GMNS supports, in short,
+Path4GMNS is an open-source, cross-platform, lightweight, and fast Python path engine for networks encoded in [GMNS](https://github.com/zephyr-data-specs/GMNS). Besides finding the static and time-dependent shortest path for simple analyses, its main functionality is to provide an efficient and flexible framework for column(path)-based modeling and applications in transportation (e.g., activity-based demand modeling). Path4GMNS supports, in short,
 
 1. finding (static) shortest path between two nodes;
 2. constructing shortest paths for all individual agents;
@@ -128,7 +128,7 @@ import path4gmns as pg
 
 network = pg.read_network()
 # you can specify the input directory
-# like pg.load_columns(nework, 'data/Chicago_Sketch')
+# like pg.load_columns(network, 'data/Chicago_Sketch')
 pg.load_columns(network)
 
 # path-based UE
@@ -174,7 +174,7 @@ pg.perform_network_assignment_DTALite(1, assignment_num, column_update_num)
 print('\npath finding results can be found in agent.csv')
 ```
 
-The OpenMP Run-Time Library must be installed to utilize the built-in parallel computing feature in DTALite (and DTALite would not be able to run if the run-time support is absent). Installation of the OpenMP run-time library varies by operating systems.
+The OpenMP run-time library must be installed to utilize the built-in parallel computing feature in DTALite (and DTALite would not be able to run if the run-time support is absent). Its installation varies by operating systems.
 
 ***Windows Users***
 

data/Lima_Network/settings.yml

@@ -7,13 +7,7 @@ agents:
     flow_type: 0
     pce: 1
     free_speed: 60
-  - type: w
-    name: walk
-    vot: 10
-    flow_type: 0
-    pce: 1
-    free_speed: 10
-  
+
 demand_periods:
   - period: AM
     time_period: 0700_0800

path4gmns/accessibility.py

@@ -3,7 +3,7 @@
 
 from .classes import Assignment
 from .colgen import _assignment
-from .consts import MIN_TIME_BUDGET, BUDGET_TIME_INTVL
+from .consts import MAX_TIME_BUDGET, MIN_TIME_BUDGET, BUDGET_TIME_INTVL
 
 
 __all__ = ['evaluate_accessiblity']
@@ -204,6 +204,9 @@ def evaluate_accessiblity(ui, multimodal=True, output_dir='.'):
     _assignment(A.get_spnetworks(), column_pool, 0)
     # update minimum travel time between O and D for each agent type
     max_min = _update_min_travel_time(column_pool)
+    if max_min > MAX_TIME_BUDGET:
+        # manual cutoff to avoid potential long computation time
+        max_min = MAX_TIME_BUDGET
     interval_num = _get_interval_id(max_min) + 1
 
     multitheading = True

path4gmns/consts.py

@@ -5,6 +5,7 @@
 MIN_OD_VOL = 0.000001
 # for accessibility evaluation
 MIN_TIME_BUDGET = 10
+MAX_TIME_BUDGET = 240
 BUDGET_TIME_INTVL = 5
 # reserved for simulation
 NUM_OF_SECS_PER_SIMU_INTERVAL = 6