How to define a step in the design interval using an optimization algorithm?

Hello experts

This question is shared with one of my research team.

We are dealing with an optimization problem in which the algorithm will choose the cross-section of the column (RC structure) between a lower and an upper bound (e.g., LB and UB).

We know that the obtained optimal values for the section can be for example 330mm.

Recently, we came across this phrase in a paper dealing with the same problem where the author stated that 'The column sections are square with dimensions of 250 mm × 250 mm to 1200 mm × 1200 mm, by a step of 50 mm'

also the author stated that : ''we created the data of the sections, in optimization process, we choose the random section from the data''

Our concern is how to oblige the algorithm to choose 50mm for the next candidate within the design interval.

Anyone knows how to do it, please?

Answer 1

[Matt J]

You can constrain an optimization variable to integers with the intcon argument. Then, you can multiply this variable by some scalar, e.g. y=50*x., to achieve another variable y that changes in increments of 50 rather than 1.

[djedoui Nassim]

Thank you Matt for your response.

How to do so for other algorithms, except GA?

[Matt J]

You can do the same thing for any algorithm that supports integer constraints.