physicslabor

% Visualization of angles and amplitude of magnetic field lines with quiver
% and contour
% made by Samuel Schmidt

% this file needs two matrices: winkel/spannungen(with the same dimensions)
% imported into the workspace of matlab
% excel --> csv --> "Home"-Tab: "Import Data": "Numeric Matrix" + rename
%

% radians converter
r = 0.0174533;

w = zeros(36, 49);
s = zeros(36, 49);

% our excel was constructed upside down kinda so we have to flip the
% matrices (note this step might be unnecessary/needs to be changed,
% depending on the imported data)
for i = 1:size(winkel,2)
    for j = 0:size(winkel,1)-1
        w(36-j,i) = winkel(j+1,i);
    end
end

for i = 1:size(spannungen,2)
    for j = 0:size(spannungen,1)-1
        s(36-j,i) = spannungen(j+1,i);
    end
end

% for some reason the angles are inverted, so we turn them back
w = w + 180;

% these two lines are basically from the quiver doc
% but with a radians conversion with r*w
u = cos(r*w);
v = sin(r*w);

quiver(u,v)
% hold allows us to plot two plots on top of each other in a quick way
hold on;
% http://matlab.izmiran.ru/help/techdoc/ref/colormap.html
colormap('jet')
% one can possibly set the line "levels" themselves
contour(s)
hold off