Try_English_LT.pdf

Transcript

1. If Takashi-kun runs
   from Hokkaido to Okinawa
   at 10 km an hour
   @canonno_blog
   Soichiro Kano
   

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2. I want to learn
   mathematical optimization in python
   OK, I prepare a toy problem.
   Well, well…
   

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3. If Takashi-kun runs
   from Hokkaido to Okinawa
   at 10 km an hour
   

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4. Conditions
   • Takashi-kun runs through 47 prefectural office
   locations (ex. Kobe city in Hyogo, Otsu city in Shiga)
   • Departure: Sapporo city
   • Destination: Naha city
   • He is so strong that he run only straight.
   • He is so strong that he can run through the mountain.
   • He is so strong that he can run over the sea.
   • He is so strong that he can run without a break.
   

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5. Guess which? He has to run for…
   A. 2.5 weeks
   B. 5 weeks
   C. 7.5 weeks
   

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6. My approach
   ① Get the locations of the 47 prefectural office, and
   calculate the distance from one to another.
   ② Define the objective (what we want to minimize)
   ③ Define the constraints
   ④ Solve！
   ※Useful packages:
   networkx: to build and draw networks
   pulp: to optimize and decide the best condition
   

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7. ①Get the locations
   website
   pandas.DataFrame
   

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8. ①Calculate the distances
   pandas.DataFrame
   pandas.DataFrame
   

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9. ② Define the objective value
   x2
   x1
   No.1
   No.3
   No.4
   No.2
   x3
   x4
   x5
   x6
   x1～x6: Boolean
   d1～d6: Distance
   

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10. ② Define the objective value
    d2
    d1
    No.1
    No.3
    No.4
    No.2
    d3
    d4
    d5
    d6
    x1～x6: Boolean
    d1～d6: Distance
    

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11. ② Define the objective value
    d2
    d1
    No.1
    No.3
    No.4
    No.2
    d3
    d4
    d5
    d6 x1～x6: Boolean
    d1～d6: Distance
    x1d1 + x2d2 + x3d3+ x4d4+ x5d5+ x6d6
    = Total distance
    

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12. ② Define the objective value
    

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13. ② Define the objective value
    

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14. ② Define the objective value
    

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15. ③ Define the constraints
    Departure・destination
    will have only ONE edge
    x1+x3+x4 = 1
    x2+x3+x6 = 1
    Others will have TWO edges
    x1+x2+x5 = 2
    x4+x5+x6 = 2
    

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16. ④ Solve
    

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17. ④ Solve
    4361km
    436.1 hours (if run at 10km/hour)
    about 18 days 4 hours
    about 2.5 weeks
    

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18. ④ Solve
    4361km
    436.1 hours (if run at 10km/hour)
    about 18 days 4 hours
    about 2.5 weeks
    

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19. The answer is: he has to run for…
    A. 2.5 weeks
    B. 5 weeks
    C. 7.5 weeks
    

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20. Check it out my Qiita page!
    Thank you!
    @canonno_blog
    

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