Scicos 4.2 If Then Else Block

[johnny]

Hello,

I'm new in using scilab/scicos and I've a problem regarding conditions
in scicos. I was thinking about using the "If Then Else block", but I
don't know how to use this one correctly. Unfortunately I couldn't
find any working example with this block in the web, so I hope I can
find support here ...

Problem:
Man with a parachute jumps out of an aircraft at 2000 meters. At 1000
meters the parachute is automatically opened, therefore the
calculation of the speed changes.

I just did this in scilab with "if ... then ... else ... end" by
changing a specific variable, but I'm not sure how to model this in
scicos!

This is the current state of my simulation, which is currently only
simulating a falling man: http://img188.imageshack.us/img188/2825/skydiverq.jpg
The value of the constant block "r" shall be changed or another
calculation (%pi * R ^2) has to be multiplied by "a".

How can I realize this behavior in scicos?

Regards
Jan

[mike]

I think you could use the "if in > 0" - block from Events and the
selector (2 inputs, 1 output) from Branching.

regards
mike

johnny schrieb:

[Serge Steer]

It is better to use a zero crossing block (for exemple +to- with z-1000
as an input (where z is the altitude)

The use the generated event to activate the parachute model (it adds a
force). You can use a switch block (first event input connected to an
event generator at t=0 and the second one to the output of the zero
crossing block.

Serge
johnny a �crit :