sweep of a parameter

[hox]

Dear ngspice users,
I want to change a parameter within a simulation loop.

.param ph=1.2V
vaph1  aph1 0 pulse 0v ph .50ns .01ns .01ns .99ns 2ns

the parameter ph should be changed in a loop

(start of loop)
while loop < 5
let loop =1
ph=loop  ??????
tran …..

let loop=loop+1
end
(end loop)

thanks for help

ho

[Robert Larice]

Hello,

  instead of changing a parameter,
     here you might get away using  `alter'

  a sketch for that looks like this

altering the second parameter of a `pulse' VSRC device
* (compile (concat "w32/src/ngspice " buffer-file-name) t)
vaph1 aph1 0 pulse 0v 0.042ns .50ns .01ns  .01ns .99ns 2ns
.control
show vaph1
let pulse_v1 = @vaph1[pulse]
* print status quo
print pulse_v1 @vaph1[pulse]
* alter the second vaph1 pulse parameter
let pulse_v1[1] = 0.43ns
alter @vaph1[pulse] pulse_v1
* verify
show vaph1
print pulse_v1 @vaph1[pulse]
.endc

Robert

[hox]

Thanks Robert, you are great,
it' running

ho

[Abhijit Kshirsagar]

Instead of assigning one at a time, like this:
let pulse_v1[1] = 0.43ns

can one assign the entire vector at once?
let pulse_v1 = [ 0 1 2 3 4 5 6 ]
?

Do I need to synthesize a vector first?

[Robert Larice]

Hello Abhijit,

you can create a vector first, I think with
let pulse_v1 = vector(7)
and then change elements of this vector with
let pulse_v1[3] = 42

or you can `compose' a vector from scratch with
compose pulse_v1 values 11 12 13 14
print pulse_v1

by the way, Don Sauer has quite some examples
for ngspice on his web page,
http://www.idea2ic.com/NGSPICE_TEMPLATES/NGSPICE%20TEMPLATES.html

I think there is an example using alter' to set apwl' voltage source.

Regards,
Robert