# Missing values

The data for all variables of a particular case (patient, sample) are entered on one row in the spreadsheet. When for one variable you do not know the value (or entry) for the case, you leave the corresponding cell blank and do not enter any data in this cell.

As a rule, the program will ignore an entry for a numeric variable when it is unable to interpret this entry as a number.

When text is entered in a cell for a numeric variable, the program will not take this case into account for calculations (it will not substitute the text value by a zero).

The following are recognized as numbers:

5.4

LOG(36.5)

LENGTH/WEIGHT (when 'Length' and 'Weight' are correctly defined variables)

LENGTH/100

The following are not recognized as numbers and are ignored for calculations:

5,8 (when the decimal symbol is not a comma)

'4.6

LOG(CONC) (when 'Conc' is not a correctly defined variable or in case the variable 'Conc' has a zero, negative or missing value)

SQRT(-9) (error!)

1/LENGTH (when 'Length' is not a correctly defined variable or in case 'Length' equals zero)