chkwon/jpor_codes

Codes for the book "Julia Programming for Operations Research"

Code Repository for "Julia Programming for Operations Research"

Lear more about the book

Currently tested with:

• Julia v1.3.0
• JuMP v0.21.2
• Optim v0.20.6

jpor_codes's Issues

Little typo errors and path errors

I've had revisited your code and recognized some brackets are missed in statements using ..Optimizer. In Julia v1.4 reading CSV-files with readdlm does not work with only the filename. using Base.joinpath could solve the problem.
Best Frank

Chaoter 6 , ssp_example1.jl or ssp_example1.jl expansion?

Hi!

How is it possible to extend the code in ssp_example1.jl or ssp_example1.jl to return "k" first shortest path from o to d and not just the first shortest?

I thank you and appreciate any advice.

The link for reading the book online seems to be down

Hello. I was trying to look at the second version of the Julia Programming for Operations Research book, but it seems like the link is not working. Here was the link that I tried.

https://juliabook.chkwon.net/book

Thanks.

using DelimitedFiles with title of the header

In the ssp_example1.jl is there any way to read the data from the title of the header? I mean, instead of start_node = round.(Int64, data[:,1]) is there another way to say start_node is the one in the .csv file that its header is "start node i"

# Data Preparation
network_data_file = "simple_network.csv"
network_data = readdlm(network_data_file, ',', header=true)
data = network_data[1]
header = network_data[2]

Avoid inv()

You should not compute x_B as x_B = inv(B)*b, but as the solution of a linear system: x_B = B\b, and check that the rank of B is equal to m

syntax: misplaced "global" declaration

Error message:

In chap10 p-median
syntax: misplaced "global" declaration

Julia version information:

Julia 1.2.0

Suggestion:

I believe the line global locations, customers, c should be inside the function optimal(p)

Error in chap1 script.jl for current stable julia

Running the first two lines of script.jl in Chapter 1:

using JuMP, GLPK
m = Model(with_optimizer(GLPK.Optimizer))

I get the following error:

ERROR: MethodError: no method matching supports_default_copy_to(::GLPK.Optimizer, ::Bool)
Closest candidates are:
  supports_default_copy_to(::MathOptInterface.Utilities.AbstractModel, ::Bool) at /home/mepstein/.julia/packages/MathOptInterface/C1XBe/src/Utilities/model.jl:693
  supports_default_copy_to(::MathOptInterface.Utilities.MockOptimizer, ::Bool) at /home/mepstein/.julia/packages/MathOptInterface/C1XBe/src/Utilities/mockoptimizer.jl:521
  supports_default_copy_to(::MathOptInterface.Utilities.CachingOptimizer, ::Bool) at /home/mepstein/.julia/packages/MathOptInterface/C1XBe/src/Utilities/cachingoptimizer.jl:165
  ...
Stacktrace:
 [1] #set_optimizer#77(::Bool, ::typeof(set_optimizer), ::Model, ::OptimizerFactory) at /home/mepstein/.julia/packages/JuMP/MsUSY/src/optimizer_interface.jl:43
 [2] #Model#7 at ./none:0 [inlined]
 [3] Model(::OptimizerFactory) at /home/mepstein/.julia/packages/JuMP/MsUSY/src/JuMP.jl:193
 [4] top-level scope at REPL[2]:1

I'm using the current stable julia (1.3.1). I know the book says it was tested on julia 1.1. Should I expect things to not work with julia 1.3? I'm new to Julia so apologies if I've done something unrelated incorrectly.