Re: [Help-glpk] a simple question about using glpk

[Andrew Makhorin]

> I am using glpk to solve scheduling problem. I encountered a simple
> problem but couldn't figure out why is that.
> The error message I got is 'lpx_load_matrix: ja[55] = 7; column index 
> out of range"
> Does this mean I cannot have fewer structural variables than variables 
> in the raw constrains.
> For example, the objective function of my problem is like this:
> 
> Min A1I1+ A2I2 + ... A6I6 (there are only six columns)
> st.
> C11 + C12 + ... + C19 = C1  (I have 9 variables here)
> ...
> 
> How could get around of this problem?

This error message means that the problem object has less than 7
columns while you attempt to specify a constraint coefficient at
column 7. You may determine the current number of columns (i.e.
structural variables) using the api routine lpx_get_num_cols().

To avoid the error make sure that you added the correct number of
columns to the problem object before calling lpx_load_mat().