MATLAB SYMBOLIC MATH TOOLBOX 5 - MUPAD Manuel d'utilisateur télécharger pdf (Page 6)

Mupad can solve systems of equations too

You often want to solve an equation or system of equations, and then substitute that solution into a third

equation. You can use the ‘subs’ function to do this

All the [1]s and [2]s here are hard to understand. Their purpose to extract the solutions from the variable

‘sol.’ Notice that ‘sol’ is in curly parentheses {} (look at the example at the top of the page) – this means

sol contains a set (which happens to contain only a single solution – but in more complicated problems

there might be more than one solution). You need to extract the solution you want out of this set. Thus,

sol[1] extracts the first (and only) element from the set. In the first example, both the solutions for x and

y are extracted and substituted into eq3. In the second example, sol[1][1] substitutes only x. In the third,

sol[1][2] substitutes only y.

Of course not all equations can be solved exactly.

1 2 3 4 5 6 7 8 9 10 11 ... 18 19

Pas de commentaire

MATLAB SYMBOLIC MATH TOOLBOX 5 - MUPAD Manuel d'utilisateur Page 6