Tip of the week
Brightstat has a built in calculator which allows you to compute new variables with existing ones. If you have measured the weight (in kg) and height (in meters) of n subjects you can easily compute the body mass index (BMI) for all subjects. If your variables are named 'weight' and 'height' the formula would be: _weight/_height^2.
The sample file 'BodyFat' contains the variables 'Weight' (pounds) and 'Height' (inches), so the formula for calculating the BMI needs some adjustment in that case: (_Weight*0.45359237)/(_Height*2.54/100)^2.
Note: In the formula a variable name is always preceded by an underscore '_'.
Editing your data
Brightstat is not intended to be a data editor. Small changes can be done without problems but be aware that editing your data in Brighstat's data window may be very time consuming, especially with larger data files.
It is strongly recommended to prepare your data for Brightstat before uploading it into the database. A period '.' will be treated as a missing value.
How to prepare your data for Brightstat
Set data filter
You can define a filter variable for your data. Analysis and graphs are then performed for selected cases only. Select 'Filter Data' from the menu and indicate which values of which variables should be included in the analysis.
Split your datafile
You can split your datafile using a categorical variable. All tests and/or graphs are then performed for the individual categories of the split variable. Select 'Split Data' from the menu and indicate one or more split variables.
Define value labels
Brightstat works best with all your variables in number format. However, for categorical variables you can define value labels. These will be used instead of the number values in output tables and graphs. In the data or the variables window select 'Define Value Labels' from the menu.
You can sort your data by clicking on the header cell of the desired variable column in the data window
Save and reuse graph templates
In the graph edit dialogue box select 'template' and save your graph as template file. You can apply this template to all graphs of the same type, e.g. a scatterplot template can only be applied to scatterplots. Until now, templates are not stored in the database, they are active only during your current session. However, subscribers can save an output with graphs and reuse the graphs as templates in later sessions.