MATLAB: Displaying a value in the plot

num2str

Hello,

I am plotting x vs y and I am taking out the maximum value of x with max(x)

Now I want to display this maximum value of x together with some text in a legend. I am trying to use num2str.. I am not sure if I am the right track.

Best Answer

I would use sprintf, for example:

x = linspace(-5,5);
y = 5-(x+2).^2;
[maxy,idx] = max(y);
figure(1)
plot(x, y, x(idx),y(idx),'pr')
legend('y(x)', sprintf('Maximum y = %0.3f',maxy))
axis([xlim    min(y) max(y)+1])

Related Solutions

MATLAB: Plotting the correct position of maximum

You also need to specify the time value in plot(). Try this

num = [0.1 0.35 0];
den = [1 3 2];
sys = tf(num,den);
figure();
step(sys);
[y, t] = step(sys);
grid
title('Respond of sytem Subjected to initial Conditoin')
xlabel('t')
ylabel('Output x(t)')
hold on;
[max1, idx1] = max(y);
[min1, idx2] = min(y);
plot(t(idx1), max1,'o')
plot(t(idx2), min1,'o')
legend('y(x)', sprintf('Maximum y = %0.4f',max1),sprintf('Minumum y = %0.3f',min1))

MATLAB: Can’t see the text on a plot, but only for some values

When I used the Symbolic Math Toolbox to create ‘odefun’, the problem became obvious. You are using the two ‘Y’ values to define the x and y coordinates for your text object.

Try this slight variation:

n = 4.2;
odefun = @(x,Y,n)[Y(2);-1.0./x.^2.*(x.*Y(2)-n.^2+x.^2)];
[x, Y]= ode45(@(x,Y)odefun(x,Y,n), [0.5, 20], [1 1]);
figure;
plot(x,Y);
title('Y as a function of x');
xlabel('x');
ylabel('Y(x)');
[max_value,idx] = max(Y);
max_x=max_value(1);
max_y=max_value(2);
txt='Max Value';
text(x(idx), max_value, txt,'FontSize', 10, 'color', 'red', 'VerticalAlignment', 'top', 'HorizontalAlignment','center')

Best Answer

Related Solutions

MATLAB: Plotting the correct position of maximum

MATLAB: Can’t see the text on a plot, but only for some values

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