[Gnucap-devel] gnucap development snapshot 2008-06-01

[al davis]

There is a new development snapshot available ... 
http://gnucap.org/devel/gnucap-2008-06-01.tar.gz

Optional plugin files are not changed except for version number
but here's a set with consistent numbering.
http://gnucap.org/devel/gnucap-2008-06-01-models-bsim.tar.gz
http://gnucap.org/devel/gnucap-2008-06-01-models-jspice3-2.5.tar.gz
http://gnucap.org/devel/gnucap-2008-06-01-models-ngspice17.tar.gz
http://gnucap.org/devel/gnucap-2008-06-01-models-spice3f5.tar.gz
http://gnucap.org/devel/gnucap-2008-06-01-tools.tar.gz

This file contains the md5sum of the other files, so you can 
check for a proper download:
http://gnucap.org/devel/gnucap-2008-06-01.md5sum

This snapshot provides:

New "measure" command, for post-processing measurements.

There is also support for "function" plugins, that are used by 
measure, and will eventually also be used by param.

There is also a "eval" command, that will evaluate a param 
expression, and if possible print the current numeric value.  
If it cannot be fully evaluated, it will be evaluated as much 
as possible and a reduced expression printed.

6 measures are included in this release.  More can be added as 
plugins, and these can be omitted or modified and used as 
plugins.

All of them take the arguments:
probe= a probe that must be among those that were stored by a 
store command.  The probe name must be quoted.

before= a number (or parameter or expression) stating to look 
only at time (or frequency or any "x") before this number.
Default is the end the run.

after= a number (or parameter or expression) stating to look 
only at time  (or frequency or any "x") after this number
Default is the beginning of the run,

Others can take additional arguments.

All arguments except probe are optional.

1. argmax()
The x value (time or frequency) at which the maximum value 
occurs.

2. argmin
The x value (time or frequency) at which the minimum value 
occurs.

3. cross
The x value (time or frequency) at which the probed signal 
crosses a value.
Additional args:
cross= a number (or parameter or expression) stating the value 
crossing to look for. Default = 0.

rise or fall = which edge.

4. max
The maximum value.

5. min
The minimum value.

6. slewrate
The slew rate, reference to two points.
Additional args:
initial= a number (or parameter or expression) stating the value 
of the signal at which to start measuring. (required)
final= a number (or parameter or expression) stating the value 
of the signal at which to stop measuring. (required)

Example (Spice format)
(build the circuit)

.store tran v(*)
.tran ......  trace all

.measure max=max("v(2)")
.measure min=min("v(2)")
.measure slew=slewrate("v(2)" 
+  initial={min+0.2*(max-min)} final={min+0.8*(max-min)})

.param period={t2-t1}
.param freq={1/(t2-t1)}
.measure t1=cross("v(2)")
.measure t2=cross("v(2)" after=t1)
.eval freq   *** prints the result

The results of a "measure" can be used as parameters.


Comments:

This is still very much a development snapshot, and should not 
be included in any distribution or CD.


===

As usual, to get started you need only the main package 
gnucap-2008-xx-xx.tar.gz .  

The other "models" packages contain the exact models from the 
various sources. 

The manual (man directory) has been omitted from the main 
tarball.  It has not been updated since the last stable 
release.  In the future, the manual source will be in a 
separate file.

If you need other models, let me know.