How to plot the difference between two plots (using shade)

Question

BN 2021-10-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1465964-how-to-plot-the-difference-between-two-plots-using-shade

评论： Star Strider 2021-10-5

Hello everyone, I have two plots like this:

plot(OBS,'Color','#007aa5')
hold on
plot(Modeled,'Color','#ff55a3')
xlabel('time step')

Now I want to illustrate the difference between these two plots by shade like the following example:

Where plot 2 is less than plot1, the difference determines by yellow sahde and where plot 2 is greater than plot1difference determine using green shade.

I attached my datasets,

Thank you in advance

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Ravi Narasimhan 2021-10-4

编辑：Ravi Narasimhan 2021-10-4

Try the solution by @Image Analyst in https://www.mathworks.com/matlabcentral/answers/180829-shade-area-between-graphs

You may need to adapt it for your case to get the different colors.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2021-10-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1465964-how-to-plot-the-difference-between-two-plots-using-shade#answer_800769

在 MATLAB Online 中打开

LD1 = load('OBS[1].mat');

OBS = rmmissing(LD1.OBS);

LD2 = load('Modeled[1].mat');

Modeled = rmmissing(LD2.Modeled);

x = 1:numel(OBS);

figure

plot(OBS,'Color','#007aa5')

hold on

plot(Modeled,'Color','#ff55a3')

patch([x(:); flip(x(:))], [OBS; flip(Modeled)], 'b', 'FaceAlpha',0.25, 'EdgeColor','none')

xlabel('time step')

xlim([min(x) max(x)])

I am not certain what the ‘y’ axis is supposed to be. If the intent is that in increases from the top to the bottom (instead of the default shown here),. provide the appropriate axis tick values, then add:

set(gca, 'YDir','reverse')

.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Star Strider 2021-10-4

在 MATLAB Online 中打开

As always, my pleasure!

LD1 = load('OBS[1].mat');

OBS = rmmissing(LD1.OBS);

LD2 = load('Modeled[1].mat');

Modeled = rmmissing(LD2.Modeled);

x = 1:numel(OBS);

x = x(:); % Force Column Vector

Lv = OBS > Modeled; % Logical Vector

ixs = strfind(Lv', [0 1])+1; % Start

ixe = strfind(Lv', [1 0]); % Stop

ix1m = [ixs(:) ixe(:)]; % Blue Sections

ixs = strfind([false;~Lv]', [0 1]); % Start

ixe = strfind([false;~Lv]', [1 0]); % Stop

ix2m = [ixs(1:numel(ixe)); ixe]'; % Yellow Sections

figure

plot(OBS,'Color','#007aa5')

hold on

plot(Modeled,'Color','#ff55a3')

for k = 1:size(ix1m,1)

idxrng = ix1m(k,1):ix1m(k,2);

patch([x(idxrng); flip(x(idxrng))], [OBS(idxrng); flip(Modeled(idxrng))], 'b', 'FaceAlpha',0.5, 'EdgeColor','none')

end

for k = 1:size(ix2m,1)

idxrng = ix2m(k,1):ix2m(k,2);

patch([x(idxrng); flip(x(idxrng))], [OBS(idxrng); flip(Modeled(idxrng))], 'y', 'FaceAlpha',0.5, 'EdgeColor','none')

end

hold off

xlim([min(x) max(x)])

This code is fragile because of the way the indices need to be calculated (the ‘start’ and ‘stop’ index vectors must have equal lengths for each colour), so I can’t guarantee that it will work for all such vectors without modification. The ‘ix1m’ vector worked straight away, however the ‘ix2m’ vector needed modification.

The resolution could be improved (if desired) by interpolating, for example:

xq = linspace(min(x), max(x), numel(x)*10);
OBSnew = interp1(x, OBS, xq)
OBSnew = 1×3550
   -0.6714   -0.6940   -0.7166   -0.7392   -0.7618   -0.7844   -0.8070   -0.8296   -0.8522   -0.8748   -0.8974   -0.9109   -0.9241   -0.9373   -0.9505   -0.9637   -0.9769   -0.9902   -1.0034   -1.0166   -1.0298   -1.0179   -1.0047   -0.9915   -0.9783   -0.9651   -0.9519   -0.9386   -0.9254   -0.9122

That would eliminate some of the gaps that are visible on zooming, and are due to the current resolution. Do the same with ‘Modeled’ and use ‘xq’ instead of ‘x’ in the plot and patch calls.

.

BN 2021-10-4