Allow only non-negative forecast result values

[Jariel]

My data is strictly positive (and zero values), and the output of a forecast should be only positive (and zero values) too.
My equation (simplified) looks something like this: y = 3 * x - 1 * z
So it's possible that a negative value arises if e.g. x is 0 and z is above 0.
But i don't want negative values, can i somehow specify that negative forecasts of y should be converted to 0?

[EViews Gareth]

Perform the forecast, then recode it:

Code: Select all

yf = @recode(yf<0,0,yf)

where yf is the name of your forecast series.

[Jariel]

Thanks.

But i would also need the forecast evaluation under the condition that all negative values are zeros. Is it possible to somehow specify it in the estimation equation?

[EViews Gareth]

No. But you can always calculate the forecast evaluations yourself using the @mape, @rmse, @theil functions.

[Jariel]

Thanks i'll look it up.