Translate and rotate a curve

I have a curve as seen below:

I need to first find a new location of the curve, multiple it with two and then rotate it 180 degree, so it will end up looking similiar to the figure below (The darker curve is similiar to my curve above starting from 0,0)

First the curve should be doubled and placed at the end of the blue curve (existing curve), then mulitple the curve with two, so it will go trough the x-axis, and then rotate 180 degrees.

Can you maybe help me with this? The data is attached.

Answer 1

[Mathieu NOE]

hello Mads

like this ?

load('pqfile.MAT')

% remove NaN and correct for size mismatch
A(isnan(A)) = [];
F(isnan(F)) = [];
A = A(3:end);
A(1) = 0; % force first value to 0

% central curve 
x1 = [ -A(end:-1:2); A];
y1 = [ -F(end:-1:2); F ;];

% top curve
x_rev = -0.1;
y_rev = interp1(x1,y1,x_rev);

% let's do a strech of x data (linear equation xnew = a x + b)
% for the x data
a = 1 - x_rev/max(A);
b = x_rev;
Atop = a*A + b;
% for the y data
a = 1 - y_rev/max(F);
b = y_rev;
Ftop = a*F + b;

% the bottom curve is the symmetrical of the top curve 
Abot = -Atop(end:-1:1);
Fbot = -Ftop(end:-1:1);

plot(x1,y1,'k','linewidth',3);
hold on 
plot(Atop,Ftop,'r');
plot(Abot,Fbot,'b');
hold off