@Karla How does Markiyan's solution differ from what you "would like to have as an answer"?

This is not a comment on the piecewise aspect of the question. I just want to point out that the trivial type of list flattening done in Adri's answer can be accomplished much more simply by appending [] (empty square brackets). Also, the digits=2 needs to be inside the parentheses of float(...) in order to be effective. With these changes, Adri's code becomes

N := 5:
Y := [seq( randpoly(x,degree=2), i=1..N )]:
X := sort( [seq(RandomTools:-Generate(float(range=1..10.0, digits=2)), i=1..N)] ):
H := seq( [x<=X[i],Y[i]][], i=1..N ):
yp := piecewise( x<=0, 0, H, 0 );

This is not a comment on the piecewise aspect of the question. I just want to point out that the trivial type of list flattening done in Adri's answer can be accomplished much more simply by appending [] (empty square brackets). Also, the digits=2 needs to be inside the parentheses of float(...) in order to be effective. With these changes, Adri's code becomes

N := 5:
Y := [seq( randpoly(x,degree=2), i=1..N )]:
X := sort( [seq(RandomTools:-Generate(float(range=1..10.0, digits=2)), i=1..N)] ):
H := seq( [x<=X[i],Y[i]][], i=1..N ):
yp := piecewise( x<=0, 0, H, 0 );

@kswong89 I wrote w(x,y) = .... You changed it to w(x,y):= ....

@kswong89 I wrote w(x,y) = .... You changed it to w(x,y):= ....

@dhonkabulo I don't know why it doesn't work, but it has nothing to do with the a[0] or with the convert(a, `local`). The plot shows up on your screen, right? with the a[0], right? Your original question was how to get the a[0] on the plot, right?

Does saving the plot to postscript work without a[0], or with "a[0]", as you originally had it?

@dhonkabulo I don't know why it doesn't work, but it has nothing to do with the a[0] or with the convert(a, `local`). The plot shows up on your screen, right? with the a[0], right? Your original question was how to get the a[0] on the plot, right?

Does saving the plot to postscript work without a[0], or with "a[0]", as you originally had it?

@awass  How does one know if a package is a module? Trial and error?

It is a good way in this case, if make the trial part with the :-. If the left operand of :- is not a module, you will quickly get an error message that says exactly that. This differs from the situation with square brackets. Nearly any expression that you can make with square brackets, as long as they are balanced, is potentially meaningful to Maple, and hence does not produce an error message.

@awass  How does one know if a package is a module? Trial and error?

It is a good way in this case, if make the trial part with the :-. If the left operand of :- is not a module, you will quickly get an error message that says exactly that. This differs from the situation with square brackets. Nearly any expression that you can make with square brackets, as long as they are balanced, is potentially meaningful to Maple, and hence does not produce an error message.

@williamov Sorry, but I have a hard time understanding your English. Anyway, see the command ?permgroup, which lets you construct a group from permutation generators. If you have Maple 17, check out the GroupTheory:-Perm... set of commands

@williamov Sorry, but I have a hard time understanding your English. Anyway, see the command ?permgroup, which lets you construct a group from permutation generators. If you have Maple 17, check out the GroupTheory:-Perm... set of commands

In my experience, the specification of the dependent variable(s) is not necessary when it is obvious from the ODE.

In my experience, the specification of the dependent variable(s) is not necessary when it is obvious from the ODE.

@Stud So, is your entire problem now solved?

 When you put a pair of numbers in parentheses, separated by a comma, what do you mean by that?