Dear UQLab team,

First of all, thank you for such an amazing UQ toolbox.

I am majoring in Aerospace engineering and is looking into wind energy topic.

As I am building the probabilistic input models, I found that when running the `uq_createModel`

function, the computational time is exceptionally long (when using the Quadrature method). I am suspecting this is because I have too many inputs marginal as reducing the number of them can make the computation faster.

The reason I am building up so many inputs is that I am trying to create different wind roses with different sector probabilities. Thus, if a standard wind rose has 30 degrees per sector, I will have 12 sectors for [0, 360] degree, while each marginal represents one sector with probability less than 1. Further, the probabilities for the 12 sectors should have a fixed sum of 1. An example of wind rose is shown below.

```
for ii = 1:n_sector
InputOpts.Marginals(ii).Type = 'Gaussian';
InputOpts.Marginals(ii).Parameters = [0.5 0.1];
InputOpts.Marginals(ii).Bounds = [0, 1];
end
```

I tried to utilise copulas to correlate the variables but failed to do so.

(I am not familiar with copulas, but I have tried all the example usages from the input manual and inference manual and still can not get a fixed value sum.)

Therefore, instead of defining dependency at the input marginal, I am currently altering the sector probabilities in the computational model to have a fixed sum even though I believe it is not recommended to do so.

Is there a way to have this dependency between these marginal when defining input models?

Thanks for any suggestion or feedback,

Jason