Sums of Squares Types -
CoStat can calculate Type I, Type II, and Type III sums of squares.
Pre-Defined Models -
CoStat comes with numerous models already defined.
This makes it very easy to set up the ANOVA -- just pick the model
from a list. You don't have
to write a Model statement as you do in SAS.
1, 2, 3, and 4 way completely randomized
1, 2, and 3 way randomized blocks
2 and 3 way nested
Split plot
Split-split plot
2 variations of split block
Latin square
Lattice
Several models with covariance
Defining Models -
If you need a model that hasn't been pre-defined,
you can modify an existing model or
create your own model.
The simple little language which describes the models
is fully described in the manual.
The system lets you easily:
Make variations of the existing models
Create your own new models
Change the format of the ANOVA table
Specify which term provides the df and MS values for each F test
Specify contrasts.
Re-use the models with other data files
Bartlett's Test -
Before performing the ANOVA, CoStat performs Bartlett's
Test for Homogeneity of Variances,
one of the assumptions of ANOVA.
Contrasts - You can specify any contrast that you want (for example,
you can compare treatment 1 vs. treatments 2, 3, and 4).
Means Comparisons Tests -
After performing the ANOVA,
CoStat can automatically run a
means comparisons test
(for example, Duncan's, Student-Newman-Keuls
(SNK), Tukey-Kramer, Tukey's HSD, or
Least Significant Difference (LSD)).
Compare Means -
performs SNK, Duncan's, LSD,
Tukey's HSD, or the Tukey-Kramer test for multiple comparisons of means.
These test are also available as part or the
ANOVA procedure.
Correlation
- calculates correlation coefficient; slope and Y intercept of
linear regression; standard errors.
Descriptive Statistics
- calculates n, sum,
mean, standard deviation, variance,
coefficient of variation,
skewness, kurtosis, maximum, minimum,
tests of normality (D'Agostino-Pearson K^2 Test),
tests for outliers (Dixon's Test, Grubbs' Test, Inter-Quartile-Range).
The procedure makes it easy to select subsets of the data for analysis.
World's best subset selection in multiple regression (All Subsets and several approximate procedures,
including the Simons2 procedure which does a dramatically
better job of finding the best subsets).
(See a description and sample run.)
Different versions of CoStat include different subset selection procedures:
CoStat includes the
All Subsets and Replace 1 procedures.
CoPlot includes a version of CoStat with the
All Subsets, Replace 1, Replace 2, Simons 1, and Simons 2 procedures.
Linearizable nonlinear regressions (several types):
Square Root (y=a+b*x^0.5),
Power (y=a*x^b), Inverse (y=a+b/x),
Inverse Power (y=a*e^(b/x)), Hyperbola (y=x/(a*x+b)),
Exponential (y=a*e^(b*x)), Logarithmic (y=a+b*ln(x)),
Hoerl's (y=a*x^b*e^(c*x)), y=1/(a+b*e^-x), y=e^(a+b*x),
and y=1-e^(-a*x)
True nonlinear regressions using the Nelder and Mead
Simplex Algorithm. You enter any equation. It will interatively
search for the best values for the unknowns.
(See a description and sample run.)
Solve simultaneous linear equations.
Tables
- calculates the probability
associated with a given test statistic, or the reverse
(the statistic associated with a given probability).
The tables included are:
Chi-square distribution
F distribution
Normal distribution
t distribution (2 tailed)
The procedure can also calculate the z transformation
of a correlation coefficient and its inverse.
Data Area
- Given x and y data columns, this
calculates the area under the curve.
Data Interpolate X Y
- Given x and y data columns and an x value, this interpolates values
between the data points to find the corresponding y value.
Or, given y, it finds x.
Date <-> Julian Date
- converts Year-Month-Date date values to/from Julian dates
(1899-12-31 = day 1).
Factorials
- Given an integer, n, this calculates n factorial, often written as n!.
Functions Closest
- This finds the x value where two functions are closest.
Function Equals Y
- Given a y value, this finds where the x value where a
function evaluates to y. This is useful for calculating an LD50.
Function Evaluate
- This procedure evaluates an equation at a series of x values.
Function Integrate
- This procedure numerically integrates an equation.
Function Minima
- Given an x value, this procedure finds a nearby minima.
Function Maxima
- Given an x value, this procedure finds a nearby maxima.
Permutations And Combinations
- Given the number of items picked and the
size of the population,
this procedure calculates the number of permutations and
combinations.
Random Numbers
- This will create a series of random integers in a specific
range.
Time <-> Seconds
- converts Hours:Minutes:Seconds.Decimal time values to/from
seconds values.