Hello,

Does anybody knows why this difference in the independent variable?

Thank you,
Basile

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Wrote

Hello,

Does anybody knows why this difference in the independent variable?

Thank you,
Basile

Hi Basile,


I'm not sure but I think it's something related to "local" and "global" variables... using the line() [MATH]t[/MATH] becomes a local variable for [MATH]i(t)[/MATH], and the "global" [MATH]t:x[/MATH] doesn't affect the function, vice versa without the line() [MATH]t[/MATH] is a global variable for q(t) so plotting the graph you implicitly write "plot q(x)".


regards,

w3b5urf3r

Hi Basile.
By default x is a global variable in SMath. When you define i(t), t is a local variable.
So, while you try plotting i(t) you get an error because t is not defined. When you define t=x, you obtain plots for i(t) and q(t)

Regards,

Oscar

Hello,

I can plot q(t) but not i(t) although I defined t:=x.

Can the definition of the functions have anything to do with that, one uses the if statement the other is as usually.

Regards,
Basile

Wrote

Hello,

I can plot q(t) but not i(t) although I defined t:=x.

Can the definition of the functions have anything to do with that, one uses the if statement the other is as usually.

Regards,
Basile

You're right, the issue is in the if statement (see the attachments)

to bypass the issue use this workaround:

[MATH]i(t)t>0)*(4*sin(5*t))[/MATH]


regards,

w3b5urf3r

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