Feature noisy=0 desired in res.sym

[Patrick Fath]

As in ngspice it's possible to manually turn off/on resistor noise, could a switch be added to res.sym, so that after creating the netlist it's created like R1 v1 v2 50 m=1 noisy=0?

[stefan]

Ok. In the mean time you can set
value="50 noisy=0"

Il Ven 6 Giu 2025, 12:51 Patrick Fath p-fath@users.sourceforge.net ha
scritto:

As in ngspice it's possible to manually turn off/on resistor noise, could
a switch be added to res.sym, so that after creating the netlist it's
created like R1 v1 v2 50 m=1 noisy=0?

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Feature noisy=0 desired in res.sym
https://sourceforge.net/p/xschem/discussion/general/thread/6b26f8c32f/?limit=25#3edd

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[Patrick Fath]

Thanks! The problem is, it will not work in Xyce as noisy=0 is a ngspice command, so as a result, res.sym will not work anymore if using Xyce. Maybe there is a better solution than just replacing the symbol?

[stefan]

you can add these attributes to the resistor instances:

name=R1
value=1k
noisy=1
m=1
format="tcleval([
  if {[sim_is_ngspice]} {
    return {@name @pinlist @value noisy=@noisy m=@m }
  } else {
    return {@name @pinlist @value m=@m }
  }
])"

[stefan]

I think you can create a res_noisy.sym symbol and add the format attribute above in the symbol.
symbols in the devices/ directory are generic and not bound to specific simulators so I prefer not to change res.sym.

[stefan]

Latest xschem commit adds res_noisy.sym that adds the noisy=1 or noisy=0 attribute if target simulator is set to ngspice.

[Patrick Fath]

Yes works great, really thanks for the contribution!