Streaming Experiments
16
Besides navigating and tracing the data set to find data of interest, StreamSmart
also lets you compare any two points in a single stream and manually add a data-
tuple as a row in your chosen columns in the Statistics Aplet. These functions are
found on the second page of the
Stream
menu, which is only active once streaming
has stopped.
Mark
and
Swap
can be used together to examine the relationship between points
in the data stream currently being traced. When you press
@MRK$
, the StreamSmart
Aplet sets a visible mark at the current tracer location. Once the mark is set, you
can trace to any other point in the stream. The StreamSmart Aplet displays the
change in both x and y between the mark and the current tracer location (see
Figure 2-9). Press
@SWAP!
to switch the tracer and mark locations.
Figure 2-9
Add
and
Setup
are also used together when you want to build your final data set,
point by point. For example, suppose a data stream represents the dampened
oscillations of a vibrating rod. In this case, you may want to collect just the
maximum of each oscillation into a data set. Press
\SETUP
to choose columns in the
Statistics Aplet for your data. Once the columns have been chosen, return to your
data stream and trace to the first point you want to keep in your data set. Press
%ADD$
to add the data as a row to your chosen columns in the Statistics Aplet.
StreamSmart briefly displays a message telling you the row to which the data point
is being exported. Continue in this fashion until you have collected all the points
you want, then start the Statistics Aplet to view and analyze your data. Table 2-4
lists the second page of menu keys and their functions.
