matlab cannot invoke gurobi

[Kang Li]

I'm a fresh man of gurobi , so I copied some correct code to start .

First I install gurobi 5.5.0 , second I set the path of maltab R2010b as the picture shows :



But when I run the code , matlab showed :Cannot invoke gurobi: no such program. 

I can seldom find information about this problem on google and it bothers me a lot .

If anyone knows how to solve this problem , please tell me , thank you very much !

[Christopher Maes]

What happens if you change to the directory C:\gurobi550\win32\matlab and run:

>> gurobi_setup

>> gurobi(1)

Can you send a screenshot of running the above commands in MATLAB?

If Gurobi is installed correctly you should see an error message like:

Error using gurobi

result = gurobi(model, params)

If you see that error message, the next thing to try is to solve the following simple model, by entering the commands below:

  clear model;

  model.obj = [1; 1; 2];

  model.A = sparse([1 2 3; 1 1 0]);

  model.sense = ['<'; '>'];

  model.rhs = [4; 1];

  model.vtype = 'B';

  gurobi(model)

If Gurobi is installed correctly you should see output like "Optimal Solution found"

Chris

[Kang Li]

Thank you for your advice .

I did as you told , and the screenshot of running MATLAB shows below : 

Then I run gurobi(1) : the result is below 

After I run your code , matlab gives the answer :

 But when I run oher code , it shows Cannot invoke gurobi : no such program 

 By the way ,my m-code is :

m=80;  

n=100;  

orig=1:m;  

dest=1:n;  

supply=round(n*rand(1,m)+1);  

demand=round(m*rand(1,n)+1);  

if sum(supply)>sum(demand)  

    demand(1)=demand(1)+sum(supply)-sum(demand);  

else  

    supply(1)=supply(1)+sum(demand)-sum(supply);  

end  

demand=demand*sum(supply)/sum(demand);  

supply=[orig(:) supply(:)];  

demand=[dest(:) demand(:)];  

cost=[orig(:) rand(m,n)];  

dlmwrite('orig',orig,' ');  

dlmwrite('dest',dest,' ');  

dlmwrite('supply',supply,' ');  

dlmwrite('demand',demand,' ');  

dlmwrite('cost',cost,' ');  

!ampl transp2.mod  

delete orig  

delete dest  

delete supply  

delete demand  

delete cost



and my mod-code is :

set ORIG;   # origins  

set DEST;   # destinations  

  

param supply {ORIG} >= 0;   # amounts available at origins  

param demand {DEST} >= 0;   # amounts required at destinations  

  

   check: sum {i in ORIG} supply[i] = sum {j in DEST} demand[j];  

  

param cost {ORIG,DEST} >= 0;   # shipment costs per unit  

var Trans {ORIG,DEST} >= 0;    # units to be shipped  

  

minimize Total_Cost:  

   sum {i in ORIG, j in DEST} cost[i,j] * Trans[i,j];  

  

subject to Supply {i in ORIG}:  

   sum {j in DEST} Trans[i,j] = supply[i];  

  

subject to Demand {j in DEST}:  

   sum {i in ORIG} Trans[i,j] = demand[j];  

data;  

set ORIG:= include orig;  

set DEST:= include dest;  

param supply :=include supply;  

param demand :=include demand;  

param cost : include dest :=  

include cost;  

option solver gurobi ;  

solve;

The writer told me the there is no problem with the code and I should install gurobi in matlab .

As you can see , the gurobi is installed correctly in matlab , so I do not know what to do now ~

[Christopher Maes]

Hi Kang,

From your screenshots I can tell that the Gurobi MATLAB interface is
correctly installed and working. However, it looks like you are not
using the Gurobi MATLAB interface. You are building a data file for
AMPL and then calling AMPL from MATLAB.

It's fine to do that, but you will need to make sure that AMPL and the
Gurobi-AMPL interface is correctly installed on your machine. In
particular, the error:

Cannot invoke gurobi: no such program

means that AMPL can't find the solver interface program named
"gurobi". You should make sure this is in your PATH.

For more information on setting up AMPL with Gurobi, please see the
following docs:
http://www.gurobi.com/documentation/5.5/ampl-gurobi-guide/

Thanks,
Chris

[Kang Li]

Thank you for your advice , I have worked it out .
The solution is to download "amplgurobilink5.5.0_mswin32" form 
http://www.gurobi.com/download/gurobi-optimizer
and copy it to the current root of matlab with AMPL.exe
and don't forget to change the "option solver gurobi" to "option solver gurobi_ampl".

However , thanks a lot , you really do me a favour !

在 2013年9月9日星期一UTC+8下午9时10分42秒，Chris Maes写道：