Using Core Statistical Functions

BellaDati allows you to apply statistical functions on existing indicators.

Available Functions

Following functions are currently available in BellaDati:

• corr(Y, X) Correlation Coefficient
• covar_pop(Y, X) Population Covariance
• covar_sample(Y, X) Sample Covariance
• regr_avgx(Y, X) Average of the independent variable (sum(X)/N)
• regr_avgy(Y, X) Average of the dependent variable (sum(Y)/N)
• regr_count(Y, X) Number of input rows in which both expressions are nonnull
• regr_intercept(Y, X) y-intercept of the least-squares-fit linear equation determined by the (X, Y) pairs
• regr_r2(Y, X) Square of the correlation coefficient
• regr_slope(Y, X) slope of the least-squares-fit linear equation determined by the (X, Y) pairs
• regr_sxx(Y, X) sum(X^2) - sum(X)^2/N ("sum of squares" of the independent variable)
• regr_sxy(Y, X) sum(X*Y) - sum(X) * sum(Y)/N ("sum of products" of independent times dependent variable)
• regr_syy(Y, X) sum(Y^2) - sum(Y)^2/N ("sum of squares" of the dependent variable)

Applying Functions

To use statistical functions:

1. go to Indicators
2. select first Indicator (Y) you want to use
3. go to Indicators settings
4. in Members aggregation select desired statistical functions
5. from the available drop-down select second Indicator (X)