Column statistics

Table window	Columns menu
Column Statistics

Calculate statistical values using one or two columns or perform a statistical analysis. The outcomes will be shown in a message box on the screen.

You can calculate:

statistics on a single column: Average, Minimum, Maximum, Sum, Count, Standard Deviation, Standard Error, and Variance;
statistics on two columns: Correlation and Covariance;
statistical analysis: Student's t-test and a -test.

Tip:

By opening the Statistics Pane of a table, you can already view the minimum, maximum, average, standard deviation and sum for each column. To open the Statistics pane, choose Statistics Pane from the View menu of the table window.

Dialog box options:

Function:	Select a statistical function. The following functions are available: Average, Minimum, Maximum, Sum, Count, Standard Deviation, Correlation, Variance, Covariance, Standard Error, t-test and -test.
Column:	Select the column for which you want to calculate the statistics. The input column should be a value column.
2nd Column:	When using the Correlation or Covariance function, select a second column which is independent from the first column.
True value:	When using the t-test, type the true value of your variable, i.e. the value to which your variable stochastically converges (m). The output value of the t-test has to be looked up in a table.
Expected:	When using the -test, select the column with the expected values. The output value of the -test has to be looked up in a table.

Tips:

To obtain statistical answers in an output column:

after you clicked OK in the Column Statistics dialog box, an expression appears on the command line of the table window;
you can always retrieve expressions by using the history of the command line, for instance by pressing the Arrow Up key on your keyboard;
replace the question mark in the expression with a column name following by the definition sign. For example, change the expression on the command line:

from:	? AVG(MyColumn)
to:	OUTCOL = AVG(MyColumn)

The Average, Minimum, Maximum, Sum, Count and Standard Deviation functions are also available through the Aggregate Column dialog box, i.e. in Aggregate functions.

The Count function counts, in a column, the number of fields which have a valid value. Any fields in the column that have the undefined value (a questionmark) are skipped.

The Count function accepts columns with a Value or a Bool domain.

The statistics are calculated according to the following formulae:

Average:
Standard deviation:
Correlation:
Variance:
Covariance:
Standard error:
Student's t-test:
test:

The TabCalc syntax for the command line is:

AVG(col)	calculate the average of column col
MIN(col)	calculate the minimum of column col
MAX(col)	calculate the maximum of column col
SUM(col)	calculate the sum of column col
CNT(col)	count the number of times that the values in col are not undefined
STD(col)	calculate the standard deviation of column col
STDEV(col)	calculate the standard deviation of column col
STDERR(col)	calculate the standard error of column col
VAR(col)	calculate the variance of column col
COV(col1, col2)	calculate the covariance of column col1 and column col2
COVAR(col1, col2)	calculate the covariance of column col1 and column col2
CORR(col1, col2)	calculate the correlation between column col1 and column col2
TTEST(TrueValue, col)
	perform a Student's t-test on column col where TrueValue is the value to which the mean of your variable stochastically converges (m).
CHISQUARE(col, colExpValue)
	perform a -test on the observed values (f_i) in enumerated column col where colExpValue is the column with the expected values (F_i).

Table window

Column Statistics