Accelerating MATLAB Performance

170 Accelerating MATLAB

®

Performance

disp(max(abs(realGradient - y2)))

5.932e-09

% Use diff - 3x faster but much less accurate than gradient()

y3 = [1,diff(y)/dt];

⇨ Elapsed time is 0.000709 seconds.

disp(max(abs(realGradient - y3)))

5e-05

The gradient function computes at each data point the central difference between the

data points on both sides of the point. This provides a more accurate result than diff, which

simply computes the difference of each adjacent pair of data points. Some alternative algo-

rithms have been suggested for varying data sizes.

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As an alternative, consider using Jan Simon’s DGradient utility on the File Excha ...