Thank you Ioannis and Sven!!!

To be frank, the kind of expression "abs(d)<0.00001 ? 0 : d" sounds to me not that much intuitive - anyway, less than zeroifclose() stuff - but probably it's just lack of experience.

It's basically just a compact if-block which you can read out like this: Is abs(d) smaller than 1e-5 ? ( <- note the literal question mark in the syntax!)

If yes, set it to zero - or else if not, then leave it at d (the old value).

This is borrowed from C I believe. The cool thing in hansl (gretl scripting) is that it also works directly with matrices if you use the dot-operators. Example (which I cannot test right now):

<hansl>

matrix M = ( I(3) .> 0 ) ? -2 : 0    # note the .>

print M

</hansl>

cheers

sven