Physics and Engineering of Radiation Detection

10.1. Standard Analysis Packages 589

Signal Analysis

Baseline and Peak Finding

Curve smoothing

Descriptive Statistics

One and Two Way ANOVA

t-Test

Survival Analysis

B.4 ProgrammingEnvironment

Origin has a powerful development environmentCode Builderto write, compile,
link, run, and debug code in its specifically designed languageOrigin C.Origin
C is fully compatible with ANSI C but also includes some features of C++. A strong
base of NAG C libraries are also available to facilitate designing of custom analysis
packages.

B.5 Examples

LetusnowhavealookatafewexamplesofOrigin usage. It should be pointed
out that here we will be performing very simple analyses, which are not meant to
analyze the effectiveness of Origin as a data analysis package. We simply want
that the user gets a glimpse of how one uses Origin and how easy it is to use as
an analysis platform.
Let us first assume that we have some data that we have gathered from a detector
at equal intervals of time. First we want to quickly look at the data and have a
qualitative idea of its time evolution. For this first we must import the data into
Origin ’s spreadsheet. The newer version of Origin has animport wizard,which
can be used to import any type of data. Import wizard is a very user friendly
interface that guides the user step wise through the data import process. At the
end, it dumps the data in the chosen spreadsheet. We use this wizard to import
the data and then plot it by first selecting the columns and then invoking theLine
command from thePlotpull down menu. This produces the desired graph as shown
on the left of Fig.10.1.16. Now, by looking at this time series we realize that there
are some periodicity in the data. The best way to determine the periodicities is to
perform a fast Fourier transform or FFT of the data. Performing FFT in Origin
is simply a matter of a few mouse clicks since a number of FFT algorithms are
already built into its library. First we select the data columns and then from the
Analysispull down menu we invoke theFFTmethod. A pop up menu appears,
where one could change the box method for FFT, choose betweenAmplitudeand
Power, and select some other functions. The result of the FFT appears in a new table
that contains frequencies, real and imaginary components, phase, and amplitude or
power. The amplitude or power density and phase are also automatically plotted in
a publication quality template as shown on the right side of Fig.10.1.16. It is obvious
that the frequencies in the data get clearly marked in the power density spectrum.
This method of finding periodicities in the data is very common. It, however, has a