MATLAB: Plot Y derivative and find resulting X value minimum

y derivative plot minimum value

, I have X and Y data as time and distance. I would like to find the derivative the Y values and plot this. Therefore yielding an acceleration time graph (2nd derivative). Next it is necessary to calculate the minimum of this curve. How do I find the derivative of the entire Y column to generate the new plot and then do I calculate the minimum with fminbnd? Thank yo.

Best Answer

Use the gradient function to calculate the first derivative, the del2 function to calculate the second derivative, and the min function to find the minimum.

Related Solutions

MATLAB: Finding the derivative of a graph

Example

t=0:0.1:10
y=t.^2
dy=gradient(y,t)
subplot(211);
plot(t,y)
subplot(212)
plot(t,dy)

MATLAB: How to draw tangent line at infleciton point

You have the slope at the inflection point as well as the ‘t’ and ‘y’ values at the inflection point, so all you need to do to draw the tangent line at the inflection point is to calculate the slope ‘b’, and that is straightforward.

I would use the gradient function to calculate the derivative, not diff, and the del2 function to calculate the second derivative, both because they are more accurate and because the result of each vector is the same length as the input vector.

Best Answer

Related Solutions

MATLAB: Finding the derivative of a graph

MATLAB: How to draw tangent line at infleciton point

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