partInt - Do partial integrations
Calling sequence:
partInt(expr,var):
Parameters
expr - The expression that is to be partially integrated.
var - variable or list of variables appearing inside ElementInt() in expr.
Synopsis:
Examples:
> partInt(ElementInt(f(x)*diff(g(x),x)),g(x));
/d \
-ElementInt(g(x) |-- f(x)|) + BoundaryInt(BdNx g(x) f(x))
\dx /
> partInt( 0 = ElementInt(f(x)*diff(g(x),x)) ,g(x));
/d \
0 = -ElementInt(g(x) |-- f(x)|) + BoundaryInt(BdNx g(x) f(x))
\dx /
> Lapl:= nab(nab(u(x,y))[i])[j] &t delta[i,j];
/ 2 \ / 2 \
|d | |d |
Lapl := |--- u(x, y)| + |--- u(x, y)|
| 2 | | 2 |
\dx / \dy /
> partInt( ElementInt(test(x,y)*Lapl) ,u(x,y));
/d \ /d \
-ElementInt(|-- u(x, y)| |-- test(x, y)|)
\dx / \dx /
/d \
+ BoundaryInt(BdNx |-- u(x, y)| test(x, y))
\dx /
/d \ /d \
- ElementInt(|-- u(x, y)| |-- test(x, y)|)
\dy / \dy /
/d \
+ BoundaryInt(BdNy |-- u(x, y)| test(x, y))
\dy /