gEDA-user: ngspice and dc sweep with "global parameter"

[David Logan <djlogan2@xxxxxxxxxxx>]

Hello. Working through the book, one of the things that it's having me 
do in pspice is plot the power as a function of resistance P(RL). We do 
this by creating a resistor, setting its value to "{RL}", adding a 
special part named "PARAM", setting "R2=2K" as name1/value of the PARAM 
part, then running a DC sweep using "Global Parameter" and "RL" as the name.

We can then plot things with respect to RL, such as -V(R2)^2*I(R2), 
where R2 is the resistor having the value {RL}. It's the graph of 
maximum power transfer, so it looks like a horked -x^2 graph.

I have found nothing comparable in ngspice. Is this correct?

I have included the pspice circuit file below, changing ony the .INC 
with the file data that was included.

David Logan

--------------------------------------------------------------

* D:\temp\testpspice\example_4_15.sch

* Schematics Version 9.1 - Web Update 1
* Sat Mar 19 07:36:22 2005


.PARAM         RL=2k

** Analysis setup **
.DC LIN PARAM RL 100 5k 100
.OP


* From [PSPICE NETLIST] section of pspiceev.ini:
.lib "nom.lib"

* Schematics Netlist *



R_R1         $N_0002 $N_0001  1k 
R_R2         0 $N_0001  {RL} 
V_V1         $N_0002 0 DC 1V 

* Schematics Aliases *

.ALIASES
R_R1            R1(1=$N_0002 2=$N_0001 )
R_R2            R2(1=0 2=$N_0001 )
V_V1            V1(+=$N_0002 -=0 )
.ENDALIASES



.probe


.END