view findZeros.m @ 1037:2d7ba44340d0 feature/burgers1d

Pass scheme specific parameters as cell array. This will enabale constructDiffOps to be more general. In addition, allow for schemes returning function handles as diffOps, which is currently how non-linear schemes such as Burgers1d are implemented.
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Fri, 18 Jan 2019 09:02:02 +0100
parents 8368beb0d1b3
children
line wrap: on
line source

% findZeros looks for solutions to the equation f(x)==0 within
% the limits lim with a granularity of h.
% Returns a sorted list of unique solutions.
function z = findZeros(f, lim, h)
    n = ceil((lim(2)-lim(1))/h);
    z0 = linspace(lim(1), lim(2), n);

    z = zeros(1,n);

    for i = 1:n
        zt(i) = fzero(f, z0(i));
    end

    zt = sort(zt);

    z = [];
    for i = 1:n
        if zt(i)  < lim(1) || zt(i) > lim(2)
            continue
        end

        if ~isempty(z) && abs(z(end) - zt(i)) < 1e-6
            continue
        end

        z = [z zt(i)];
    end

    % z = unique(z);
end