Vernier Spectro Pro User Manual
Page 49
Spectro Pro Reference
Spectro Pro
8
move the function into view. Once a part of the function is in view, it is
usually easy to adjust the parameters to get a good fit.
If your graph starts at x = 0, one way to get the function into view at the
start is to adjust the y-intercept value to match that of your data. Then
you will see at least a portion of the function, allowing you to adjust
other parameters as needed.
Clicking Create Column will place a new column in the data table
containing the value of the fitted equation at each x-axis value.
The Perform Fit On menu allows you to select the column used for
calculating the Mean Square Error value. The Mean Square Error
measures how far away the function is, on average, from the data.
Automatic curve fits seek to minimize this value.
Integral performs a numerical integration on the selected data.
First drag across the desired region of your data to select. Then
choose Integral (or click on the Integral button on the toolbar). You will
have the opportunity to specify which data set you want to integrate. The
numerical result is shown on the graph, and the corresponding area
shaded.
The Statistics item displays a dialog showing statistical measures
of the selected data: maximum, minimum, mean, standard
deviation, and the number of points used. You may optionally select a
region of the data first. The entire data set is used when no selection is
made. After you select Statistics (or click on the Statistics button on the
toolbar) you will have the opportunity to specify for which data set you
want statistics calculated. The statistics are presented in a floating box
on the graph screen.
The standard deviation is found using N-1 weighting, or
(
)
σ
=
−
−
∑
1
1
2
N
x
x
i
.
The first item in the View menu changes depending on the active
window. For example, to see Data Table Options, click once on a data
table before pulling down the View menu. Options settings for Text, and
Meter windows are also available.
Integral
Statistics
View menu