Help needed how to model about yalps HOT 1 CLOSED

Hi @gruijter, sorry for the late response -- I missed your issue.

This should be a simple fix. Rather than specifying the equations (row-wise), YALPS works by taking in variables (column-wise) (this API was inherited from js-lp-solver). So, you just need to "transpose" variables like this:

{
  direction: 'maximize',
  objective: 'totalCost',
  constraints: { SoC: { min: 0, max: 5 } },
  variables: {
    cs: {
      totalCost: 0.5,
      SoC: 2
    },
    ds: {
      totalCost: -0.3,
      SoC: -1.5
    }
  }
}
/*
{
  status: 'unbounded',
  result: Infinity,
  variables: [ [ 'ds', Infinity ] ]
}
*/

Note that this model gives a result of Infinity, since for each additional 1 cs, you can also increase ds by 1.333 to offset the SoC. This additional 1.333 ds only decreases the total cost by 0.4 whereas the 1 cs has a total cost of 0.5, meaning there was net gain of 0.1. This can be repeated infinitely, leading to the unbounded result. If ds's SoC was slightly lower, say -1.2, then the result will be finite:

{ status: 'optimal', result: 1.25, variables: [ [ 'cs', 2.5 ] ] }

from yalps.