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matlabmupad

Display expression and result of calculation in MuPad

Imagine I define two variables within a MuPad Notebook:

x:=2;
y:=5

For the product

z=x*y

I get displayed:

enter image description here

And if I use hold, I can get the expression:

z=hold(x*y)

enter image description here

But now I'd like to have both, the expression displayed and the result. The two options which appeared logical to me, do not worK:

z=hold(x*y);z

and

z=hold(x*y);eval(z);

enter image description here

How can I get displayed the expression AND the result? If in two lines it would be alright, but I'd prefer in one line like:

z = x y = 10

Solution

  • I tried some combinations with print, expr2text, hold and _concat but couldn't find a convincing solution to get the desired result. But there is an explanation why the second line just returns z and not 10.

    Assignment vs. Equation

    z is the result in the second line because you didn't assign something to z yet. So the result says that z is z. In MuPad = is part of an expression. The assignment operator is := and therefore not the same as in Matlab. The only difference between them is the colon.

    Writing an equation

    For writing an equation, we use = as part of the expression. There is an equivalent function: _equal. So the following two lines generate the same result:

    x+y = 2
_equal(x+y, 2)

    result1

    Assign value to x

    For an assignment we use := (in Matlab this would be only =). There is an equivalent function: _assign. So again, the following two lines generate the same result:

    x := value
_assign(x, value)

    result2

    Assign the equation x+y = 2 to eqn

    Here we can clearly see the difference:

    eqn := x+y = 2
_assign(eqn, _equal(x+y, 2))

    result3