Plotting multiple piecewise functions onto the same graph

Question

Margherita Carlon 2019-8-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/477014-plotting-multiple-piecewise-functions-onto-the-same-graph

评论： Star Strider 2019-8-22

Hi!

I'm new to the program and i've been trying to plot two piecewise functions,

y(x) = piecewise(0<x<1.85, sin(523.26*pi*x), 1.85<x<3.7, 0, 3.7<x<5.55, sin(523.26*pi*x), 5.55<x<7.4, 0, 7.4<x<9.25, sin(523.26*pi*x));

and

y2(x) = piecewise(0<x<1.63, sin(463.08*pi*x), 1.63<x<3.26, 0, 3.26<x<4.89, sin(463.08*pi*x), 4.89<x<6.52, 0, 6.52<x<8.15, sin(463.08*pi*x));

onto the same graph, but i can't get the coding right. Would anyone be able to help?

Thank you so much in advance

2 个评论
显示无隐藏无

darova 2019-8-21

Maybe you have some coding so we can correct it?

Margherita Carlon 2019-8-21

Oh absolutely,

I couldn't find any support for this specific case but what I tried was this (which is probably way off:

syms y1(x)

y1(x) = piecewise(0<x<1.85, sin(523.26*pi*x), 1.85<x<3.7, 0, 3.7<x<5.55, sin(523.26*pi*x), 5.55<x<7.4, 0, 7.4<x<9.25, sin(523.26*pi*x));

fplot(y1)

hold on

syms y2(x)

y2(x) = piecewise(0<x<1.63, sin(463.08*pi*x), 1.63<x<3.26, 0, 3.26<x<4.89, sin(463.08*pi*x), 4.89<x<6.52, 0, 6.52<x<8.15, sin(463.08*pi*x));

fplot(y2)

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2019-8-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/477014-plotting-multiple-piecewise-functions-onto-the-same-graph#answer_388486

I coded and ran ‘y1’ as:

y1 = @(x) ((0<x) & (x<1.85)).*sin(523.26*pi*x) + ((1.85<x) & (x<3.7)).*0 + ((3.7<x) & (x<5.55)).*sin(523.26*pi*x) + ((5.55<x) & (x<7.4)).*0 + ((7.4<x) & (x<9.25)).*sin(523.26*pi*x);
t = linspace(-5, 20, 500);
figure
plot(t, y1(t))
grid

Do the same for ‘y2’. Choose as many points as you want for ‘t’.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Margherita Carlon 2019-8-22

Oh I see!! Now it works perfectly :)

do you happen to have any tips on how to change the number of points for t? Given it's really high-frequency, the mapped function dosen't look too sinusoidal anymore...

Star Strider 2019-8-22

Change the third argument in the linspace function to change the number of points it creates. (The default number is 100.) See the documentation section on Vector with Specified Number of Values.

请先登录，再进行评论。