Flipping a curve to match another in a figure

Is it possible to flip the top curve to match the other one at bottom to match the red circled area. I have attached the dataset if you want to try.

Answer 1

[DGM]

I'm not really sure what you're expecting, but you can flip it easy enough.

plot(XX,YY,'b'); hold on;

xmax=max(XXXX);
ymax=max(YYYY);
plot(xmax-XXXX,ymax-YYYY,'k');

Though I have a feeling that simple flipping isn't a good solution. Consider that the two series used to share endpoints. Perhaps it would be better to flip across a line connecting the endpoints:

https://www.mathworks.com/matlabcentral/answers/408075-how-can-i-reflect-a-part-of-a-plot-on-a-vector#answer_326927

Using that example:

%% using line reflection
clear; clc; clf
load('XX.mat');
load('YY.mat');
load('XXXX.mat');
load('YYYY.mat');

plot(XX,YY,'b', 'DisplayName', 'XX,YY'); hold on;

x=XXXX; % the example script uses these names
y=YYYY;
xx=[max(x) min(x)];
yy=[min(y) max(y)];

slope = (yy(2)-yy(1))/(xx(2)-xx(1))
intercept = yy(1)-xx(1)*slope

% Calculate slope and y-int of line perpendicular to reflection line
perpSlope = -1/slope; 
yInt = y - perpSlope.*x;
% Find where each point (x,y) crosses the reflection line
% These should all lie on the reflection line
xintersect = (yInt-intercept)/(slope-perpSlope);
yintersect = slope*xintersect + intercept;
% Shift each (x,y) point to the origin and rotate 180 deg
% more info: http://math.sci.ccny.cuny.edu/document/show/2685
xs = x - xintersect; 
ys = y - yintersect; 
xr = xs * cos(pi) - ys * sin(pi); 
yr = xs * sin(pi) + ys * cos(pi); 
%shift back to original positions, but reflected.
xFinal = xr + xintersect; 
yFinal = yr + yintersect; 
% Plot the data
plot(xFinal, yFinal, 'k', 'DisplayName', 'ReflectedData')
rh = refline(slope, intercept); 
rh.DisplayName = 'ReflectionLine';
legend()