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gnucap:manual:commands:dc [2020/02/15 15:03]
felixs [Comments]
gnucap:manual:commands:dc [2023/01/31 08:51] (current)
felixs add parameter sweeps, marked as "soon"
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 ===== Purpose ===== ===== Purpose =====
  
-Performs a nonlinear DC steady state analysis, and sweeps the signal input, or a component value. +Performs a nonlinear DC steady state analysis, and sweeps the signal input, or a component value or (soon) a parameter value. Components must be of type "element", such as voltage/current sources and resistors.
  
 ===== Syntax ===== ===== Syntax =====
  
   dc start stop stepsize {options ...}   dc start stop stepsize {options ...}
-  dc label start stop stepsize {options ...} +  dc label start stop stepsize {options ...} 
 +  dc param start stop stepsize {options ...}
  
 ===== Comments ===== ===== Comments =====
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 If there are numeric arguments, without a part label, they represent a ramp from the generator function. They are the start value, stop value and step size, in order. They are saved between commands, so no arguments will repeat the previous sweep. If there are numeric arguments, without a part label, they represent a ramp from the generator function. They are the start value, stop value and step size, in order. They are saved between commands, so no arguments will repeat the previous sweep.
  
-A single parameter represents a single input voltage. Two parameters instruct the computer to analyze for those two points only.+A single argument represents a single input voltage. Two arguments instruct the computer to analyze for those two points only.
  
 In some cases, you will get one more step outside the specified range of inputs due to internal rounding errors. The last input may be beyond the end point. In some cases, you will get one more step outside the specified range of inputs due to internal rounding errors. The last input may be beyond the end point.
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 The program will sweep any simple component, including resistors, capacitors, and controlled sources. SPICE sweeps only fixed sources (types V and I). The program will sweep any simple component, including resistors, capacitors, and controlled sources. SPICE sweeps only fixed sources (types V and I).
    
-This command will sweep up to 4 components, nested.+This command will sweep up to 4 component values or parameters (soon), nested.
  
-The original models of the sweep component(s) will be restored after the simulation has been completed.+(Soon:) Sweeping parameters may be noticeably slower than an equivalent element sweep, as all parameters are re-evaluated before each step. Time used is added to the setup function timer (cf. [[gnucap:manual:commands:status|status]]). 
 + 
 +The original models of the sweep component(s) and parameter values will be restored after the simulation has been completed.
  
 ===== Options ===== ===== Options =====
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 Sweep the circuit input from -10 to +15 in steps of 1. (usually volts.) Do a DC transfer simulation at each step. Sweep the circuit input from -10 to +15 in steps of 1. (usually volts.) Do a DC transfer simulation at each step.
   dc   dc
-With no parameters, it uses the same ones as the last time. In this case, from -10 to 15 in 1 volt steps.+With no arguments, it uses the same ones as the last time. In this case, from -10 to 15 in 1 volt steps.
   dc V13 -10 15 1   dc V13 -10 15 1
-Sweep the "value" of the component "V13" from -10 to +15 in steps of 1. Do a DC transfer simulation at each step.+Sweep the "value" of the element "V13" from -10 to +15 in steps of 1. Do a DC transfer simulation at each step. (Soon:) If there is no element by this name, but a parameter, then sweep the parameter instead.
   dc 20 0 -2   dc 20 0 -2
 You can sweep downward, by asking for a negative increment. Sometimes, this will result in better convergence, or even different results! (For example, in the case of a bi-stable circuit.) You can sweep downward, by asking for a negative increment. Sometimes, this will result in better convergence, or even different results! (For example, in the case of a bi-stable circuit.)
gnucap/manual/commands/dc.txt · Last modified: 2023/01/31 08:51 by felixs
 
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