Lambda SR1, Operation Manual, Page: 201 / 317

SR1 Operation 201
© 2014 Stanford Research Systems
over the input data range. RMS or Linear averaging can be selected. A third option,
variance, does not return the average but rather the variance: the RMS average
deviation from the mean.
2-sigma Returns a trace containing a constant value which exceeds 95% (2 ) of the y values
within the input data range.
Linearity Calculates a linear fit to the data within the input range and then returns a trace equal
to the
difference of the input data and the linear fit.
Smooth Returns a "smoothed" version of the data in the input range. The smoothing algorithm is
selected from the calculator panel.
Invert Returns a trace containing the "inverted" y-data within the input rage. For data
displayed in logarithmic units, the y-values are sign-inverted and translated so that the
original data and the inverted data have the same value at the "invariant" X-Value
selected on the panel. For linearly scaled input data the inverted value is equal to the
reciprocal of the ratio of the original y-value to the invariant y-value multiplied by the
invariant y-value.
Normalize After selecting a target X and Y value, this routine returns a scaled version of the input
data such that the new trace has the selected Y-value at the selected X-value.
Delta Returns a trace containing the difference between the two selected input traces over
the input data range. If the input data is in dB units, the difference between the dB
values is calculated.
Multiply Returns a trace containing the product of the two selected input traces.
Equalize Returns a trace containing the input data weighted by the selected EQ file.
Ratio Returns a trace containing the ratio of the two selected input traces.
Trim "Trims" the input data do the selected input data range. The returned trace has
identical Y-Values to the input trace but only contains points within the specified X-
range.
Unwrap Returns a trace with the "unwrapped" version of the input phase-frequency trace.
Unwrapping is done by inserting 360 jumps at appropriate break points in the phase
vs. frequency curve.
Group
Delay Returns a trace equal to the Group Delay of the input phase vs. frequency trace. Group
delay is defined as the derivative of the radian phase with respect to frequency.
Parametric Displays a parametric plot of the two selected input traces with their common X-axis as
a parameter. Each pair of Y values from the two input traces are used to create an X,Y
pair in the returned trace. For instance, if the same trace is selected for both inputs the
result will be a straight line with a slope of one whose extent in X and Y is equal to the
Y range of the input data. The selected trace Y-values become the Y values for each
point, the second trace Y-values furnish the X-values for the displayed points.
MakeEQ Create an saves an EQ file corresponding to the selected trace. The selected X-value is
assigned a value of "1" in the EQ file. All other points are scaled relative to that point.
Make ARB Creates and saves an ARB file corresponding to the selected trace. The resulting file
can be used by the
arbitrary waveform generator.