DADiSP Software
Modules - DADiSP/Stats - Statistics
 DADiSP/Stats
is a menu-based module designed to perform a variety of statistical tests
and present statistical information graphically. The DADiSP/Stats module
computes statistical measures, calculates probability values based on
standard distributions, displays summary reports and graphics and performs
hypothesis tests on sample data.
Each menu option pops up a dialogue box that provides you with a description
of the menu feature and prompts for the location of your sample data.
The results of the statistical test are displayed automatically on the
screen.
Key Features
- Simple User Interface
- Descriptive Statistics
- Column and Row Statistics
- One and Two Tailed T Tests
- Chi Square Tests for Multiple Categories
- F Tests
- Two Sample Comparison T Tests for Pooled Variances
- Two Sample Comparison T Tests for Unequal Variances
- One Way ANOVA
- Hypothesis Testing
- Multiple Regression
- Residual Plots
- Scatter Plots
- Histograms
- Box and Error Plots
DADiSP/Stats is a menu-driven module for DADiSP that computes statistical
measures, calculates probability values based on standard distributions,
displays summary reports and graphics, and performs hypothesis tests on
sample data.
Industry Standard Measurements
DADiSP/Stats uses DADiSP's familiar graphical Worksheet and pull-down
menus. All of the DADiSP analysis and graphics features are available
to operate on original input data and on the results of statistical operations.
The statistics module offers an additional dimension to DADiSP, providing
scientists and engineers with accepted industry statistical measurements
to analyse quantitative data.
Descriptive Statistics
Sample size, mean, median, variance, standard deviation, standard error,
maximum, minimum, and range values are immediately avaliable at the click
of a button. Any computation can be used as a stand alone value for further
computation or presented as a group in a summary report. Statistical computations
can be performed on single datasets or tables with row or column orientation.
Graphical Statistical Analysis
Mean, median, variance, error bar and box plots provide quick visual summaries
of common statistical properites. Xbar, Range and combined Xbar/Range
plots are appropriate for quality control and process management applications.
Histograms, scatter plots and residual plots further complement the statistical
visualisation features of DADiSP/Stats.
Regression Analysis
Linear and Polynomial fitting offer straightforward statistical modelling
capabilities. Sophisticated multiple regression techniques model data
with a linear combination of almost any user defined terms. Regression
statistics, residual and comparison plots aid in the interpretation of
regression results. Chi square goodness of fit statistics provide standard
acceptance probabilities and significance levels for regression coefficients.
ANOVA
DADiSP/Stats includes powerful Analysis of Variance routines. Variation,
sum of squares, degrees of freedom and mean squared statistics are computed
for average, between and within sample groups. F ratio, F probability
and significance levels for hypothesis testing are automatically displayed.
Data Comparison
T test sample comparison for pooled and unequal variances compute significance
levels for variance testing. One and Two Tailed T tests calculate statistical
measurements for mean testing. F Ratio test, cross-correlation, R and
R^2 correlation coefficents provide additional tools for statistical data
comparison.
Probability Generation
Chi squared, Normal, T Test and F probability density functions are easily
generated to provide common standards for several statistical measurements.
Lookup functionality is optimised to produce fast and accurate results.
Data Management
DADiSP can access data from external binary or ASCII files, from other
software packages, or directly from the keyboard. The importing and data
management features allow you to read single or multi-column tables. A
dataset may be stored as a multi-variate table or as a set of individual
series. Data can be read into DADiSP for a one-time data processing session
or stored the data in DADiSP permanently.
Integrated Results
Each menu option in the statistics menus pops up a dialog box that provides
a description of the menu feature and prompts the location of the sample
data. The results of each statistical test are displayed automatically
on the screen. Each menu option generates a presentation quality screen
report or graph that contains the statistical results and text summaries.
Each report or graph can be incorporated into a document or sent directly
to the printer.
Verification and Automation
The underlying statistical macros and menus can be viewed to verify the
statistical algorithms or adapt the individual routines to particular
applications. DADiSP/Stats was developed using DADiSP's custom menu and
macro extension language. The menu and macro files are simple ASCII text
files. The statistical functions are fully documented, including formulas
and source references. While DADiSP/Stats is completely menu-driven, any
of the new statistics features can be accessed from the command line or
from one of DADiSP's automated session scripts.
See function list...
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