---student_movement.nlogo

NETLOGO

patches-own [ barrier]
breeds [ inside
         outside ]
globals [ time
          num-outside
          num-inside ]

to setup
    ca
    ask patches [ setup-school]      ;;setup hallways
    setup-students                   ;;place students
    set time 0
    setup-plot
    update-monitors                 ;;reports number of students left
    update-plots
end

to setup-school
    set pcolor gray + 4
    ifelse ( pycor > 16 ) [ set barrier true ] [set barrier false]                 ;;top boundary
    if ( pxcor < -3 ) and ( pycor > -9 ) and ( pycor < 11 ) [ set barrier true ]   ;;left block     
    if ( pxcor > 3 ) and ( pycor > -9 ) and ( pycor < 11 ) [ set barrier true ]    ;;right block
    if ( pxcor = -17 ) and ( pycor > 4 ) [ set barrier true ]                      ;;left wall
    if ( pxcor = 17 ) and ( pycor > 4 ) [ set barrier true ]                       ;;right wall
    if barrier = true [ set pcolor red - 2 ]                                       ;;indentifies barrier
end

to setup-students
        
    create-inside num-students-in                                            ;;choose number of students starting inside
    ask inside [ setxy ( 0 + random 16 - random 16 ) 14 ]                    ;;puts turtles in random line inside building
    create-outside num-students-out                                          ;;choose number of students starting outiside
    ask outside [ setxy (random screen-size-x) -14 ]                         ;;puts turtles in random line outside building
    set-default-shape inside "student"
    set-default-shape outside "student-boy"
    ask turtles [if count turtles-here > 1 or barrier = true    
                    [find-new-spot]]                                          ;;turtles begin separated
end

to setup-plot                                               ;;puts data into graph
    set-current-plot "Students Left"
    set-plot-y-range 0 num-students-in + 10
end

to find-new-spot
    rt random 360
    fd 1
    ifelse count turtles-here > 1 or barrier = true        ;;turtles cannot be on the same spot as another turtle, or on a barrier
        [find-new-spot] [set heading 180]
end

to go
     ifelse wait-inside? [ask inside                       ;;turtles will have to wait if the switch is engaged
                              [if time > wait-time
                                  [ go-inside ]]]
                         [ask inside [go-inside]]
     ifelse wait-outside? [ask outside 
                              [if time > wait-time
                                   [go-outside]]] 
                  [ask outside [ go-outside ]] 
     if count turtles > 0 [ set time time + .01 ]         ;;time will be recorded in order to keep track of how long the model has been running.  
     update-monitors                                      ;;it will stop when there are no more turtles on the screen
     if count turtles > 0 [ update-plots ]
end

to go-inside
    ask inside [ifelse (xcor < 0) [set heading 90 + random 90 ] [set heading 270 - random 90] ]    ;;sets heading in the general direction of the hallway
    ask inside [if ((pcolor-of patch-at dx dy) = red - 2 and xcor < 0) [lt 90 ]]                   ;;to avoid walking within the barriers
    ask inside [if ((pcolor-of patch-at dx dy) = red - 2 and xcor > 0) [rt 90 ]]
    ask inside [ 
          ifelse (any turtles-at dx dy) 
              [set heading heading + random 90 - random 10]    ;;turtles can only move if the space is not occupied by another turtle and the space is not a wall
              [if pcolor-of patch-at dx dy != red - 2 
                  [fd .01]]]
    ask inside [if (ycor <= -15) [ die ]]         ;;after the turtles reach their destination, they die
end

to go-outside 
    ask outside [ifelse (xcor < 0) [set heading 90 - random 90 ] [set heading 270 + random 90] ]   ;;sets heading in the general direction of the hallway
    ask outside [if ((pcolor-of patch-at dx dy) = red - 2 and xcor < 0) [rt 90]]                   ;;to avoid walking within the barriers
    ask outside [if ((pcolor-of patch-at dx dy) = red - 2 and xcor > 0) [lt 90]]
    ask outside [ 
          ifelse (any turtles-at dx dy)
              [set heading heading + random 90 - random 10]    ;;turtles can only move if the space is not occupied by another turtle and the space is not a wall
              [if pcolor-of patch-at dx dy != red - 2
                  [fd .01]]] 
    ask outside [if (ycor >= 15) [ die ]]         ;;after the turtles reach their destination, they die
end

to update-monitors               ;;records the number of turtles left to reach destination
    set num-inside (count inside)
    set num-outside (count outside)
end

to update-plots                  ;;plots the number of turtles left to reach destination
    set-current-plot-pen "num-inside"
    plot num-inside
    
    set-current-plot-pen "num-outside"
    plot num-outside
end
@#$#@#$#@
GRAPHICS-WINDOW
251
21
720
490
17
17
13.4
1
10
0
0

CC-WINDOW
303
504
618
624
Command Center

BUTTON
14
21
81
54
NIL
setup
NIL
1
T
OBSERVER

SLIDER
18
99
190
132
num-students-in
num-students-in
0
100
25
1
1
NIL

SLIDER
19
150
191
183
num-students-out
num-students-out
0
100
70
1
1
NIL

BUTTON
128
21
191
54
NIL
go
T
1
T
OBSERVER

MONITOR
17
201
82
250
NIL
time
3
1

MONITOR
17
259
103
308
NIL
num-inside
3
1

MONITOR
17
319
111
368
NIL
num-outside
3
1

PLOT
771
34
1209
482
Students Left
Time
Students
0.0
15.0
0.0
100.0
true
false
PENS
"default" 100.0 0 -16777216 true
"num-inside" 0.01 0 -65413 true
"num-outside" 0.01 0 -16776961 true

SWITCH
18
384
150
417
wait-inside?
wait-inside?
0
1
-1000

SLIDER
18
464
190
497
wait-time
wait-time
0
7
0.5
0.1
1
NIL

SWITCH
18
420
158
453
wait-outside?
wait-outside?
1
1
-1000

@#$#@#$#@
WHAT IS IT?
-----------
Confliction flow is a problem with movement in many situations.  In order to clear the congestion and find the most efficient way to move, the agents must organize for what is best for the group.  In this model, the setting of a school provides a problem when students are trying to get from class to class.  When class ends, students exit classrooms in large masses, intending to get to the next class within a time limit set by a bell schedule.  However, there are students both coming in from the outside and gong out from the inside.  Students are slowed down by other students that are crowded around them and by other students trying to go in the opposite direction.  This model offers a demonstration of how changing certain parameters can organize student movement within a school's hallways as students are both entering and exiting the building to get to the next class.


HOW IT WORKS
------------
All students are going to the opposite location of where they begin.  If a students starts inside, his destination is outside, and vise versa.  When each student exits his initial class, he sets his heading toward the hallway.  If the student encounters other students in his paths, he will turn to a general right direction to avoid a collision.  If he encounters a wall, he will also turn right or left (depending on his current position) toward the direction of the hallway.  The student will not be able to go forward if he is blocked by a wall or another student.  When the student reaches his destination, he will disappear into the classroom.


HOW TO USE IT
-------------
Press SETUP to set the layout of the model.
Press GO to begin the model.

NUM-STUDENTS-IN: This slider allows one to change the number of students that originate from inside the building.
NUM-STUDENTS-OUT: This slider allows one to change the number of students that originate outside the building.
WAIT-INSIDE?/WAIT-OUTSIDE?: These switches allow one to decide if the students inside or outside wait a certain time before trying to get to the next class.
WAIT-TIME: This slider allows one to decide how much time the students will wait if either of the wait? switches are engaged.


THINGS TO NOTICE
----------------
The monitor TIME will log how much time has passed.  You can use this monitor to see how changes in variables cause a change in time needed for all students to reach their destinations.
The monitors NUM-INSIDE and NUM-OUTSIDE keep a count of how many students are still on their way to their destinations.
The graph STUDENTS LEFT give a visual to the monitors on how many students are left.