TSP (JobSolveStatus.INFEASIBLE_SOLUTION: 3)

Question

Well I'm trying to code de travelling salesman prolem but when a get to the solution part my code prints
"JobSolveStatus.INFEASIBLE_SOLUTION: 3"
I don't know what's happening, but I leave my code below

My df are 20 cities and I'm using cities from Mexico

import pandas as pd
df = pd.read_excel(open('Mydataframe.xlx','rb'),sheet_name='Hoja1', converters={'n°':int}, index_col=[0])
df
df["Coordenadas"]=""
df
import googlemaps
gmaps_key=googlemaps.Client(key="My Api Key")
for n in range(len(df)):
geocode_resultado=gmaps_key.geocode(df.iloc[n][0])
try:
lat=geocode_resultado[0]["geometry"]["location"]["lat"]
lon=geocode_resultado[0]["geometry"]["location"]["lng"]
df.set_value(n,"Coordenadas",(lat,lon))

except:
lat=None
lon=None

from pandas import ExcelWriter
from pandas import ExcelFile

write=ExcelWriter('/Users/chico/Desktop/Ahora si lo resuelvo/F.xlsx')
df.to_excel(write,'Hoja1', index=False)
write.save()
df

from geopy import distance
import numpy as np

distancia=[]

for n in range(len(df)):
for i in range(len(df)):
if n!=i:
distancia.append(np.round(distance.distance(df.iloc[n][1],df.iloc[i][1]).km,
decimals=1))

print(distancia)

ciudades=[i for i in range(len(df))]
ciudades

arcos=[(i,j) for i in ciudades for j in ciudades if i!=j]
print(arcos)

distancia_arcos={(i,j):distance.distance(df.iloc[i][1],df.iloc[j][1]).km for i,j in arcos}
distancia_arcos

from docplex.mp.model import Model

mdl=Model('TSP-2')
x=mdl.binary_var_dict(arcos,name='x')
d=mdl.continuous_var_dict(ciudades,name='d')

mdl.minimize(mdl.sum(distancia_arcos[i]*x[i] for i in arcos))

for c in ciudades:
mdl.add_constraint(mdl.sum(x[(i,j)] for i,j in arcos if i==c)==i,ctname='out_%d'%c)

for c in ciudades:
mdl.add_constraint(mdl.sum(x[(i,j)] for i,j in arcos if i==c)==i,ctname='in%d'%c)

#The rest of the code will be in the comments

Answer 1

Rather than pasting the code in Description section (it's a big code) and end up getting the text truncated from character limits - save your code in your profile, edit your question and share the link in Description section of the original question above.

Having the code link available in the Description section, you can then safely remove the code text from Description section (keep problem description intact), also remove the rest of code in answers section. People prefer to open your code for a review rather than copying some text - paste into code for testing (more hustle).

Here's how to share links and tips for posting a question. For future reference 👍

P.S. Please don't reply, I will remove this note if you update your original question.

https://www.sololearn.com/post/74857/?ref=app
https://www.sololearn.com/Discuss/333866/?ref=app

Answer 2

#This is the rest of the code

for i,j in arcos:
if j!=0:
mdl.add_indicator(x[(i,j)],d[i]+1==d[j],name='order_(%d,_%d)'%(i,j))

print(mdl.export_to_string())

mdl.parameters.timelimit=60
mdl.parameters.mip.strategy.branch=1

solucion=mdl.solve(log_output=True)

mdl.get_solve_status()

#in this part mi code prints <JobSolveStatus.INFEASIBLE_SOLUTION: 3>
#An then when i want my optimal solucion a code this:

solucion.display()

#And just prints "AttributeError: 'NoneType' object has no attribute 'display'"