How to improve the accuracy of drawing, especially for infinite functions？

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dcydhb dcydhb 2019-5-13

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评论： hasan s 2022-1-13

in some plot assignments,we can use 'ezplot' to plot the more accurate figure but for infinite functions the 'ezplot' still can't plot it accurately,so how can we improve the accuracy of drawing, especially for infinite functions？

functions and codes are as this

syms m1;
g=9.8;
h=20;
hgang=20;
omega=2;
nu=omega^2*hgang/g;
g = @(m1) (i*m1)*tanh(i*m1)-nu;
fplot(g,[-10,20])
ylim([-60,40])

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采纳的回答

Walter Roberson 2019-5-13

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Use fplot() instead of ezplot()

And skip using inline(): inline() has been recommended against since MATLAB 5.1

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Walter Roberson 2022-1-13

在 MATLAB Online 中打开

If you have discontinuities and you want to use plot(), then you need to take one of two approaches:

Detect the discontinuities (somehow) and insert a nan at that location so that MATLAB stops drawing there; OR
Use your knowledge of the formulas to draw the lines in pieces, using hold on

If you use the Symbolic Toolbox and you write in terms of piecewise() then fplot() will detect the discontinuities and use vertical lines.

syms a b c d x real

part0 = piecewise(x<=a | x >= d, 0, 0);

part1 = piecewise(x>b & x < c, 1, 0);

part2 = piecewise(x > a & x <= b, (x-a)./(b-a), 0);

part3 = piecewise(x > b & x <= d, (d-x)./(d-c), 0);

f = part0 + part1 + part2 + part3

f =