How to plot this?

%Invert the data to use findpeaks to find the valleys

negdepthFeet = -depthFeet;

dur = duration(15,0,0);

% Use findpeaks

[lowerLowWater,lowerLowUTC] = findpeaks(negdepthFeet,

tideTime,'MinPeakProminence',10/12,'MinPeakDistance',dur);

lowerLowWater = -lowerLowWater;

MLLWmud = mean(lowerLowWater);

MLLW = 0;

% Tide level in feet relative to MLLW

feetMLLW = (depthFeet-MLLWmud);

Answer 1

[Star Strider]

I am not certain what you want to plot, since you did not specify that.

Try this:

tideTime = linspace(0, 4*pi);                                   % Create  Data
depthFeet = cos(5*tideTime).*sin(tideTime);                     % Create Data

negdepthFeet = -depthFeet;

[lowerLowWater,lowerLowUTCidx] = findpeaks(negdepthFeet);

lowerLowWater = -lowerLowWater;
MLLWmud = mean(lowerLowWater);
MLLW = 0;

figure
plot(tideTime, depthFeet)
hold on
plot(tideTime(lowerLowUTCidx), depthFeet(lowerLowUTCidx), 'vr')
hold off
grid

Experiment to get different results.