Ploting a wave with different colors in the same figure [duplicate]

问题

How can I plot a wave (represented by 1 x N matrix) with different colors in matlab. The range for a specific color can be provided manually.

See the diagram below for the expected output.

回答1:

Here is a simple option:

x = linspace(-4*pi,4*pi,10000); % some data
y = -sin(x); % some data
N = 4;
py = reshape(y,[],N);
px = reshape(x,[],N);
plot(px,py,'LineWidth',2)

Where y is your vector, and N is the number of pieces you want to distinguish. Note that you have to make sure that y is dividable by N with no remainder.

If you want to set the colors, you can do this with set command:

p = plot(px,py,'LineWidth',2)
cmap = parula(N); % a set of N colors in RGB matrix
set(p,{'color'},mat2cell(cmap,ones(N,1),3))

and you get:

回答2:

That figure looks like a sine function, so let's just assume that it is for this example. While I don't have MATLAB in front of me right now, what I would probably do is, in an m-file script:

clear all; clc;
functionToPlot = [sin(0 : (pi/2) : (8*pi))]; %This spacing will look very sharp and pointy, so I'd recommend using >>linspace like shown in other answers.
yAxisVector = [-1 : 1 : 1];
for n = 1 : length(functionToPlot)
    if rem(functionToPlot(1,n),2) <= pi
        plot(functionToPlot(1,n),yAxisVector,'r')
        hold on
    elseif rem(functionToPlot(1,n),4) <= pi
        plot(functionToPlot(1,n),yAxisVector,'g')
        hold on
    elseif rem(functionToPlot(1,n),6) <= pi
        plot(functionToPlot(1,n),yAxisVector,'y')
        hold on
    elseif rem(functionToPlot(1,n),8) <= pi
        plot(functionToPlot(1,n),yAxisVector,'c')
        hold on
    end
end

This code should give you the function that you pictured in your question. Have you tested a code yet? What code did you test? This link shows an alternative method using RGB values, if you prefer that. Good luck with your project!

来源：https://stackoverflow.com/questions/45505927/ploting-a-wave-with-different-colors-in-the-same-figure

标签

matlab

matlab-figure