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Putting multiple data sets on the same graph

Question asked by JERRY_MARKETOS on Sep 1, 2005
Latest reply on May 29, 2008 by NWHITE
Putting multiple data sets on the same graph

This is done easily in Genesys, with a little lesson in syntax...

The syntax for a measurement on a graph is as follows:

analysis.datasource.measurement

To further clarify, let's assume we have set up a very
simple schematic (named SCH1)  with a linear analysis (named linear1)
and we wish to obtain the S21 response of whatever is on the schematic....

The measurement entered into the graph properties measurement area would be

linear1.sch1.s21

Genesys works hard to make things easy, so it provides a default data path
at the top of each graph that eliminates the user having to type the first two parts.
Rather, they are chosen in the "default data" dropdown at the top of the graph
properties box, and only the measurement part, S21 needs to be entered.
(There are many other measurement variations such as ang(s21), real(s21) etc.
These are documented in the online Genesys Help.

Progressing from this, if we had two or more schematics and wanted to
place S21 measurements from both on the same graph, we could take two
approaches:

A)
We could set the default data path at the top of the graph properties to, say,
linear1.sch1   then enter S21 in the first measurement line, then perhaps
enter the full syntax in the second measurement line  linear1.sch2.s21

B)
We could ignore the default data dropdown altogether and just enter
the full syntax in both measurement lines:
linear1.sch1.s21
linear1.sch2.s21

Some other notes and tips:

The above discussion example used a single linear analysis with multiple schematics,
but Genesys can do much more than that.  You can use multiple linear analyses
(of different frequency spans) combined with different measurements.  For instance
linear1.sch1.s21
linear2.sch2.s22
linear1.sch2.s11

...would all be acceptable on the same graph.  You might want to consider the
specific numeric value of the data to be graphed, the graph auto scale feature
(which can be turned off) will track the widest overall dynamic range, and data
sets that have relatively small dynamic range will become difficult to read when
combined with datasets of larger range.  Genesys offers the capability to use
two vertical axes (that's the "on right" checkbox in graph properties) as a means
of further flexibility with this.  Alternatively, you may wish to place data of significantly
different numeric range intentionally on different graphs.

You can also mix measurements from different engines, such as displaying
data from linear analysis on same graph as data from EM analysis.  Here's where
we need to have a little discussion on syntax for data from EM analysis...

If the layout being analyzed doesn't contain any cosimulated lumped components
from the schematic, then the process is standard as one might expect....

EM1.layout1.s21

If cosimulated components do exist, then the correct syntax is

Linear1.EM1.s21   (the EM1 analysis contains reference to a specific layout)

Truth is most often Genesys is smart enough to recognize and do the right
thing when cosimulated components exist, but the correct syntax is given here
in the interest of thoroughness and accuracy.

Thus (for example) in one graph we could have all at the same time

Linear1.sch1.s21
EM1.layout1.s21
linear1.sch1.s11   (probably on right)
EM1.layout1.s11  (probably on right)

... and several others also if we desired.  

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