The data statistics in MATLAB plot does not show the correct value

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Farooq 2022-10-10

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https://ww2.mathworks.cn/matlabcentral/answers/1821503-the-data-statistics-in-matlab-plot-does-not-show-the-correct-value

编辑： Torsten 2022-10-11

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Intro to engineering MATLAB courseware course.

I have a plot of a projectile, where y-axis is the height of the projectile, and x-axis is the time.

When I view the 'Data Statistics' in the drop down tools on the plot, it shows me the correct maximum value for y, but for the maximum value of x it just shows 20 for all the plots. 20 is the maximum the axis goes, but I need the time it took for the projectile to hit the ground, so the maximum x value for each plot. As you can see in the plot below for theta = 10, x should be less than 5 but it shows 20.

The code is:

% initial speed in m/s
V0 = 90;
% angle in degrees
theta = [10,25,45,65,85]';
% initial height above the ground in meters
y0 = 0;
% time in seconds
t = 0:0.01:20;
% gravity in m/s^2
g = 9.81;
% x position of the projectile in meters
xposition = (V0.*cosd(theta)).*t;
% y position of the projectile in meters
yposition = (-0.5*g.*(t.^2))+((V0.*sind(theta)).*t)+y0;
%% plotting the yposition of the projectile vs the time
plot(t , yposition)
xlabel('Time (s)')
ylabel('Projectile Height (m)')
ylim([0 500])
legend('Theta = 10', 'Theta = 25', 'Theta = 45', 'Theta = 65', 'Theta = 85')

Please could you help.

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Adam Danz 2022-10-11

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Once the ball hits the ground, it's y value should remain at y=0 for the remainder of the time (assuming no bounce). So you'll see flat lines at y=0 after the curves reach the ground.

That's an easy change.

Hint:

max(yposition,0)