How do I change the value of the HEAVISIDE function from NaN to 1/2 when in Symbolic Math Toolbox 3.2 (R2007a)?

The HEAVISIDE function is desigedn to return NaN for x== 0. I would like the HEAVISIDE function to return 1/2 instead.

When I execute:

f=heaviside(sym('0'))

The ouput is:

 f =

 NaN

How can I modify the output of 'heaviside(sym('0'))' to 1/2 instead of NaN?

Answer 1

[MathWorks Support Team]

The value of heaviside(sym('0')) can be altered form NaN to any value (say 1/2). This can be achieved by modifying the status of 'heaviside()' in Maple, which is 'undefined' by default, in the Maple Kernel.

You can do this as follows:

At the MATLAB command prompt, type:

maple('At_zero_return_one_half := proc(f,X)     if f = Heaviside and X[1] = 0 then   NumericStatus(invalid_operation=false);1/2;else undefined;end if;end proc:');

maple('NumericEventHandler( invalid_operation = At_zero_return_one_half ): forget(Heaviside):');

This will assign the value 1/2 to heaviside(0) in the Maple kernel.

You can verify that you obtain the expected behavior:

   f=heaviside(sym('0'))

returns:

 f =

 1/2

Once you have completed the task, if you desire to clear these settings on HEAVISIDE, please type:

maple restart

to restart Maple