Hi,
Make sure you have a license for this toolbox and it is correctly installed by using:
ver
ver gives you a list of currently installed products. If the toolbox is not in this list, it is not installed. If you have license for it, install it using this guide. If you do not have a license for it, you could purchase one or you will not be able to use the features of the toolbox.
A further thing you can try is:
which biograph
which gives back the location where the the function is stored on the computer - if it exists in the Matlab search path.
For example:
>> which ode45
C:\Program Files\MATLAB\R2018a\toolbox\matlab\funfun\ode45.m
If you find the biograph.m file this way i would suggest to reinstall the toolbox.
Best regards
Stephan
