How to add a patch to a plot of data?

Hi,

I have a plot of Data (wavelength vs transmission) and I was to highlight sections on the plot independent of y axis. Imagine highlighting certain wavelengths along the x axis. I think I need to use a patch function but not sure how to define the rectangle shape ontop of the existing data plot and get it to match.

Answer 1

[Star Strider]

I am not certain what your function or data are or what you want to plot.

See if this helps to cliarify the general approach —

x = linspace(0, 10, 500);
y = sin(2*pi*x/5);

idx = find(diff(sign(y-0.5)))                           % Regions Greater Than 0.5

idx = 1×4

21 104 271 354

idxm = reshape(idx,2,[])

idxm = 2×2

21 271 104 354

figure
plot(x, y)
yl = ylim;
hold on
for k = 1:size(idxm,2)
    xrng = idxm(1,k) : idxm(2,k);
    patch([x(xrng) flip(x(xrng))], [min(ylim)*ones(size(y(xrng))) flip(y(xrng))], 'r', 'FaceAlpha',0.5)
end
hold off
grid

.