VARIANCE

Variance of Trace Amplitudes

Returns the amplitude variance of the specified trace, in measurement units.
Syntax
.
.
VAR I ANCE
Item Description/Default Range
User-defined trace
A
trace
delined
by the TRDEF command. Any valid trace name.
Trace range
A
segment of trace
A,
trace B, trace C, or a user-defined trace.
Prerequisite Commands: TRDEF when using a user-defined trace. TS when using trace data.
Related Commands: MEAN, RMS, STDEV.
Example
OUTPUT
718;"IP;"
OUTPUT
718;"SNGLS;TS;"
OUTPUT 718;"VARIANCE
TRA?;"
ENTER 718;Number
DISP
Number;"MEASUREMENT
UNITS"
Description
Initializes analyzex
Activates single-sweep mode.
I&turns variance of trace A to computer:
Stores value in computer variable.
LXsplu~s the results on computer screen.
‘lkking
the square root of a variance yields the standard deviation value.
The formula to calculate the variance is as follows:
n-l
n represents the number of data points.
xi
represents a data point.
X
represents the mean of data.
5-584 Programming Commands