CoStat's Statistical Procedures
(multiple and non-linear regression, nonparametric tests,
GLM ANOVA, multiple comparisons of means, analysis of frequency data,
correlation, descriptive statistics, etc.)

CoStat has a wide range of statistical procedures.

• Each procedure has a short description in its dialog box.
• Statistical results are sent to a text editor window (CoText), where they can be viewed, edited, printed, and saved to a file.

Here is a list of the procedures:

• ANOVA (Description of ANOVA)
  • CoStat's ANOVA procedure can do ANOVAs with:
    • Missing values
    • Unbalanced designs
    • a priori contrasts
    • Covariance
    • Up to 10 factors
    • User-specified models
  • Sums of Squares Types - CoStat can calculate Type I, Type II, and Type III sums of squares.
  • Defining Models - A unique model description system makes it easy for anyone to run standard analyses by picking the appropriate model from a list. The system allows more advanced users to modify existing models or create their own models in order to specify more complex or unusual models. The system lets you easily:
    • Make variations of the existing models
    • Create your own new models
    • Change the format of the ANOVA table
    • Re-use the models with other data files
  • Pre-Defined Models - CoStat comes with numerous models already defined:
    • 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
  • Bartlett's Test - Before performing the ANOVA, CoStat performs Bartlett's Test for Homogeneity of Variances, one of the assumptions of ANOVA.
  • 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.
   
• 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.
   
• Analysis of Frequency Data ( Description of Analysis of Frequency Data)
  • Cross tabulation of string or numeric data.
  • Calculation of expected frequency of normal, binomial, or Poisson distributions.
  • Goodness of Fit Tests - Kolmogorov-Smirnov, Likelihood Ratio (G test), and Chi-square tests of goodness of fit.
  • Fisher's Exact Test.
  • Log-linear analysis of 3 way tables.
     
• Miscellaneous Tests
  • Confidence Limits of a Correlation Coefficient
  • Confidence Limits of a Mean
  • Confidence Limits of a Regression Coefficient (Slope)
  • Equality of Two Means (equal variances) (t Test)
  • Equality of Two Means (unequal variances) (t test)
  • Equality of Two Percentages (G test)
  • Equality of Two Variances (F Test)
  • Homogeneity of Correlation Coefficients
  • Homogeneity of Linear Regression Slopes
  • Homogeneity of Variances (Using n and Variance Data) (Bartlett's Test)
  • Homogeneity of Variances (Using Raw Data) (Bartlett's Test)
  • Mean±2SD - summarized data in a format that it is easy to plot in CoPlot.
  • Single Observation and a Mean (t Test)
     
• Nonparametric Tests ( Description of Nonparametric Tests)
  • Percentiles - calculates nonparametric descriptive statistics: mode and percentiles.
  • Rank Correlation - Kendall's and Spearman's Rank Correlation Tests are analogous to the Pearson product moment correlation coefficient.
  • 2 Runs Tests - Up and Down, and Above and Below the Median
  • Tied Ranks - ranks the values in a column, replaces ties with the average rank, then inserts a new column with the tied rank values.
  • 1 Way, Completely Randomized ANOVA - using the Kruskal-Wallis Test.
  • 1 Way, 2 Treatment, Completely Randomized ANOVA - using the Mann-Whitney U-test and Wilcoxon Two Sample Test.
  • 1 Way, Randomized Blocks ANOVA - using Friedman's Method for Randomized Blocks.
  • 1 Way, 2 Treatment, Randomized Blocks ANOVA - using Wilcoxon's Signed-Ranks Test for Two Groups.
     
• Regression
  • Polynomial regressions of any order.
  • Periodic (Fourier) curve fitting.
  • Multiple regression (including Backwards Elimination and All Subsets options). ( Description of Multiple Regression)
  • Several types of linearizable nonlinear regressions.
  • True nonlinear regressions using the Nelder and Mead Simplex Algorithm. You enter any equation. It will interatively find the best values for the unknowns. ( Description of Nonlinear Regression)
  • 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.
   

• Utilities
  • 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).
  • Degrees°Min'Sec" <-> Degrees.dd - converts Degrees°Min'Sec" values to/from decimal degrees values.
  • 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.
     

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