Question

Write a MATLAB function named myaccel that accepts three inputs and has a single output.

Inputs:

1. a list of time values
2. a list of position values
3. a single time value.

Output:

1. a single number which is obtained by numerically differentiating position with respect to time twice (forward difference method) and then interpolating the results based on the third input.

Example:

time=0:10;
position=time.^3;
myaccel(time,position,2.8) % should return 22.8 

Answer 1

Fucntion Code

function y = myaccel(time,pos,tq)
pval = pos(time);
h = time(2)-time(1);
y2 = zeros(1,length(time));
for i=1:length(time)-2
y2(1,i) = (pval(i+2)-2*pval(i+1) + pval(i))/h^2; %Formula for forward difference second order
end
y = interp1(time,y2,tq); %interpolation function
end

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Script code to call above function

syms time
position = matlabFunction(time.^3); %Position function defined
time = 0:10;
y = myaccel(time,position,2.8)

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Results

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