[FEATURE] Rounding of small values to 0

[dqpinel]

Motivation

Some values are very small and cause numerical problems while solving

Feature Description

Some values are very small and cause numerical problems while solving.
Example in EnVis_Green:
TradeLossFactor of Gas_Natural -> 9.45e-7, H2 ->5e-6, Power 3e-5
Residual_Capacity, FRT_Rail_Conv-CH-2040 -> 4e-5
Another example are RHS values for constraint OC2 for HMHI_Steam_Electric where a residual capacity gets multiplied with the Fixed cost resulting in values in the 1e-6 range.

This might not affect GAMS, as I think it automatically rounds to 0 everything that is too small. However in julia, the data is read as is, causing a very big matrix range and numerical instability.
It could be preferable to find out the internal threshold in GAMS and apply to the data during the processing to even out the behaviours across the versions.

Even better would be an individual threshold that could be set for each parameter defining the minimum possible values (other than 0) to improve the numerical stability while keeping the details where they are necessary, for instance when numbers end up getting multiplied by something large like the trade loss factors.

[loeffko]

@dqpinel Yes, GAMS rounds to ~8 digits, so everything below that is always considered true zero. Also, we are rounding several numbers and results to 4 digits after the comma to make it easier.

So I agree that we should probably do part of this already in the data directly. However, some things will just materialize within e.g. the timeseries reduction, so part of it could/should probably be handled in the model code as well.

@julianbornemann Maybe we could add some functionality to round numbers to a certain threshhold in the data conversion script? And then maybe optimally as Dimitri suggested with a mapping table in the Set_filters_file so that we can set a default (e.g. 10E-06) but could set specific rounding values for specific parameters?