Dividing lists into data sets and plotting

If you have a comma separated dataset that contains X values and two sets of Y values for each X. I need to create two new data sets with X and Y values. You can pull out each set using the subsop and seq commands.
Here is my data set
$data="[10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500]";
I want to divide this into three data sets
X 10, 40, 70 ...
Y1 20,50,80...
Y2 30,60,90..
To do this, first we divide the data sets
$m=maple(" K := $data; X := subsop(seq(`if`(`mod`(i, 3) = 1, NULL, i = NULL), i = 1 .. nops(K)), K); Y1 := subsop(seq(`if`(`mod`(i, 3) = 2, NULL, i = NULL), i = 1 .. nops(K)), K); Y2 := subsop(seq(`if`(`mod`(i, 3) = 0, NULL, i = NULL), i = 1 .. nops(K)), K); ");
To plot one of these series we can use
plot(Vector(X), Vector(Y1), style = point, symbol = asterisk, color = `blue`)
To plot both on the same graph we can use the plots[display] function.
plots[display]( plot(Vector(X), Vector(Y1), style = point, symbol = asterisk, color = `blue`), plot(Vector(X), Vector(Y2), style = point, symbol = asterisk, color = `red`) )
The full code looks like this
$data="[10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500]"; $m=plotmaple(" K := $data: X := subsop(seq(`if`(`mod`(i, 3) = 1, NULL, i = NULL), i = 1 .. nops(K)), K): Y1 := subsop(seq(`if`(`mod`(i, 3) = 2, NULL, i = NULL), i = 1 .. nops(K)), K): Y2 := subsop(seq(`if`(`mod`(i, 3) = 0, NULL, i = NULL), i = 1 .. nops(K)), K): plots[display]( plot(Vector(X), Vector(Y1), style = point, symbol = asterisk, color = `blue`), plot(Vector(X), Vector(Y2), style = point, symbol = asterisk, color = `red`) ) ");
The result is