Hello Andrew,
constraint
s.t. cost {i in N, j in N} :
t[i] - t[j] - sum{(i,j) in E} c[i,j] * x[i,j] = 0;
leads to error
0-ary slice not allowed
in glpmpl01.c, function expression_list.
My expectation was that the sum is 0 if (i,j) is not an element of E and
c[i,j] x[i,j] otherwise. This
constraint
s.t. cost {i in N, j in N} :
t[i] - t[j] - sum{(i,j) in E} c[i,j] * x[i,j] = 0;
leads to error
0-ary slice not allowed
in glpmpl01.c, function expression_list.
My expectation was that the sum is 0 if (i,j) is not an element of E and
c[i,j] x[i,j] otherwise. This would be
constraint
s.t. cost {i in N, j in N} :
t[i] - t[j] - sum{(i,j) in E} c[i,j] * x[i,j] = 0;
leads to error
0-ary slice not allowed
in glpmpl01.c, function expression_list.
My expectation was that the sum is 0 if (i,j) is not an element of E and
c[i,j] x[i,j] otherwise. This
Do you agree that the following notation is meaningless?
sum{(2,3) in E} c[i,j] * x[i,j]
This is exactly the same as your example: the composite index has no free
dummy variables.
Hello Andrew:
My understanding of common indices is that they are a shorthand for unnecessary
equality
Hello Andrew,
Just for clarity.
Do you agree that the following notation is meaningless?
sum{(2,3) in E} c[i,j] * x[i,j]
The following model is correctly solved by GLPK:
set E := {(2,3)};
var v{(i,j) in E};
s.t. con1 {(i,j) in E} : v[i,j] - sum{(2,k) in E : k == j} 1 = 0;
var w{(i,j) in
Just for clarity.
Do you agree that the following notation is meaningless?
sum{(2,3) in E} c[i,j] * x[i,j]
The following model is correctly solved by GLPK:
set E := {(2,3)};
var v{(i,j) in E};
s.t. con1 {(i,j) in E} : v[i,j] - sum{(2,k) in E : k == j} 1 = 0;
var w{(i,j) in E};
s.t.
