MATLAB: What is the equation for this graph

equationgraph

Best Answer

I give you the first section and you extend it along the x-axis

    x = 0:0.001:0.04;
    y = (800.*x-4).*(x>=0 & x<0.01) + 4.*(x>=0.01 & x<0.02) + (-400.*x+12).*(x>=0.02 & x<=0.04);
    plot(x,y)
    grid on
    axis([0 0.04 -6 6])

Related Solutions

MATLAB: 2d filled contour plot

Try this:

x = [0;0.03;0.03;0.01;0.01;0;0.02;0.02;0.01;0;0.01;0.02;0.015;0.005;0.025;0.03;0.025;0.01;0.005;0;0.01;0.005;0];
y = [0;0;0.01;0.01;0.04;0.04;0;0.01;0.025;0.025;0;0.005;0.01;0.005;0;0.005;0.01;0.0175;0.025;0.0125;0.0325;0.04;0.0325];
z = [0.002071017;0.002090221;0.001384402;0.001358957;0;0;0.002078694;0.001373731;0.000432053;0.000422168;0.002069412;0.001727074;0.001369789;0.001713017;0.002084764;0.00173648;0.00137873;0.000855225;0.000414625;0.001187851;0.000125043;0;0.000124721];
N = 15;
xv = linspace(min(x), max(x), N);
yv = linspace(min(y), max(y), N);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x,y,z,X,Y,'linear');
figure
contourf(X, Y, Z, 'ShowText','on')
xlabel('x')
ylabel('y')

Change ’N’ to get different results.

MATLAB: Is this not working

First, it appears that you are trying to solve it inside the functions, and that won’t work.

Second, this:

F(9) = 0.01*x(6) + 0.04*x(7) - 0.01*X(9);
                                    ↑ ← HERE

MATLAB is case-sensitive, so ‘x’ and ‘X’ are different.

This works:

function [F] = MyFunc(x);
F = zeros(9,1);
 
F(1) = 300 - x(1) - 50000*x(4).^2;
F(2) = x(1) - x(2) - 50000*x(5).^2;
F(3) = x(1) - x(3) - 50000*x(6).^2;
F(4) = x(2) - x(3) - 25000*x(7).^2;
F(5) = x(2) - 100 - 50000*x(8).^2;
F(6) = x(3) - 100 - 50000*x(9).^2;
F(7) = 0.04*x(4) - 0.01*x(5) - 0.01*x(6);
F(8) = 0.01*x(5) - 0.01*x(8) - 0.04*x(7);
F(9) = 0.01*x(6) + 0.04*x(7) - 0.01*x(9);
end
x0 = [200, 150, 100, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5];
x = fsolve(@MyFunc,x0)'

and produces:

x =
          277.777777777778
          188.888888888889
          188.888888888889
        0.0210818510677892
        0.0421637021355784
        0.0421637021355784
      2.57436435034422e-19
        0.0421637021355784
        0.0421637021355784

Best Answer

Related Solutions

MATLAB: 2d filled contour plot

MATLAB: Is this not working

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