[ANN] SymbolicUtils.jl -- Groundwork for a symbolic ecosystem in Julia

[simeonschaub]

@fkguo

then 0a gives 0 * a , but 0b gives the following error:

This is because 0b1011 is syntax for creating an unsigned integer from binary. You need to explicitely write 0*b in this case.

[fkguo]

Thanks.

@fkguo

In version v0.4.3 , @syms a; 0* a gives zero, while in the new version v0.5.0 , it gives 0 * a . How can I force it to be zero?

figured out this can be done using r = @rule (0 * ~a) => 0; r(0*a) gives zero. But would it be better to give zero automatically in this case?

[shashi]

On v0.5.0 we stopped simplifying expressions to print them.

@syms a; 0* a gives zero

It wasn’t actually returning zero but printing zero rather confusingly.

You can call simplify(0*a) to get 0.

[fkguo]

@shashi

You can call simplify(0*a) to get 0.

got it. many thanks. but would it be better to automatically simplify such a case?

[shashi]

You could define that yes, but it would be a kludge. We would have to define many methods and check that one of the inputs is a number and is zero.

[shashi]

Now we do automatically simplify this and a number of other common cases. simplify itself is rarely needed now :}

[fkguo]

That’s great! Thanks.