how do I make script that plots values from workspace dividing into the case

i have workspace where it has two valuables 'X'&'Y' .Each valuable has 10001 dates(this date is randam numbers from -3.14 to 3.14 and they are vector X is10001x1,Y is 10001x1)

Using this,I want to make a script that make a line graph.i want to use numbers from valuable X on x axis and from valuable Y on y axis from top to bottom, but when the sign of numbers of X and Y is same,don't plot and skip to next number.

I know how to plot dates from workspace on graph,but i don't know how to write underlined part.please help!

Answer 1

[Chunru]

x = randn(101, 1);
y = randn(101, 1);
idx = x.*y > 0;     % same signs
plot(x(~idx), y(~idx), 'ro'); grid on

[拓郎 岡畑]

thank you for your question!i can make a suitable script by your support