Plotting wind magnitude time series and direction as indicator arrows

Hi all,

I am trying to plot wind time series for 1 point, where I have magnitude and direction. I would like to have a regular 2D plot of the magnitude but then I want to add an arrow indicating the direction at each plotted point in time, as shown in the attached figure.

would appreciate any help executing this or other suggestions to plot magnitude and direction time series (other than the straightforward ways obviously (e.g.,quiver..etc)

Cheers,

NZ

Answer 1

[VINAYAK LUHA]

Hi Nayef,

It is my understanding that you have a time series dataset where each datapoint corresponds to some wind magnitude, additionally you have an array representing the wind direction at these datapoints. You want to know an alternate way than using the traditional “quiver” function to represent wind direction using arrows at these plotted data points.

Here’s a possible workaround for your reference-

Hi Nayef,

It is my understanding that you have a time series dataset where each datapoint corresponds to some wind magnitude, additionally you have an array representing the wind direction at these datapoints. You want to know an alternate way than using the traditional “quiver” function to represent wind direction using arrows at these plotted data points.

Here’s a possible workaround for your reference-

% Generating random data 
time = 1:10; 
magnitude = [3 6 4 8 5 7 6 9 4 7]; 
direction = [30 45 60 75 90 105 120 135 150 165]; %in degrees 

% Plotting magnitude 
plot(time, magnitude, 'b', 'LineWidth', 2); 
hold on; 

% Add arrows indicating the direction 
arrowLength = max(magnitude) * 0.05; 
arrowX = time; 
arrowY = magnitude; 
arrowAngle = deg2rad(direction); 
arrowXEnd = arrowX + arrowLength * cos(arrowAngle); 
arrowYEnd = arrowY + arrowLength * sin(arrowAngle); 

for i = 1:numel(time) 
    drawArrow([arrowX(i), arrowY(i)], [arrowXEnd(i), arrowYEnd(i)], 'r', 0.08, 25); 
end 

% Custom function to draw an arrow 
function drawArrow(startPoint, endPoint, color, lineWidth, tipAngle) 
    % Calculate arrowhead points 
    arrowLength = norm(endPoint - startPoint); 
    arrowHeadLength = arrowLength * tan(deg2rad(tipAngle)); 
    arrowHeadWidth = arrowHeadLength / 2; 
    arrowHeadPoints = [0, arrowHeadWidth; arrowHeadLength, 0; 0, -arrowHeadWidth]; 

    % Rotate and translate arrowhead points 
    theta = atan2(endPoint(2) - startPoint(2), endPoint(1) - startPoint(1)); 
    R = [cos(theta), -sin(theta); sin(theta), cos(theta)]; 
    arrowHeadPoints = (R * arrowHeadPoints')'; 
    arrowHeadPoints = arrowHeadPoints + endPoint; 

    % Draw arrow 
    line([startPoint(1), endPoint(1)], [startPoint(2), endPoint(2)], 'Color', color, 'LineWidth', lineWidth); 
    patch(arrowHeadPoints(:, 1), arrowHeadPoints(:, 2), color, 'EdgeColor', color, 'LineWidth', lineWidth); 
end 

Regards

Vinayak Luha