Generation of similar vectors

Hi every one,

I have a vector of points which represents a regressive form (as shown in the attached file). This vector containes 1112 samples and i want to generate similar vectors with the same trend (regressive). However, i want that these vectors have different length (=/= 1112) by knowing tha the threshold is equal to 1.

To summirize, i want to know how to generate vectors with the same trend of the original one bu with different length, exp: 2000, 500, 400, etc. and the final amplitude of each vector is equal to the threshold (1).

Thank you very much for our attention and your help.

Best regards

Answer 1

[darova]

What about interp1()?

load data.mat
y = data;
x = 1:length(y);

x1 = linspace(x(1),x(end),1000);
y1 = interp1(x,y,x1);

plot(x,y,x1,y1,'r')

Look also for spline()

[moncef soualhi]

Hi,

Thank you very much for your help, it's working. However, this script generate vectors with different length but it seems like a translation of the original one. For this purpose, i want to try to generate the vectors, but based on generalized equation extracted from the original vector in order to have different forms not only one trajectory.

As a summurize, from the original one, i want to create others with the same trend but different form?

I don't know if it is possible?

Thank you verry much for your help

[darova]

Play with the parameters to get the result you want

clc,clear

load data.mat
y = data;
n = length(y);
x = (1:n)';
x0 = x(1:20:end);                   % frequency of course noise
noise1 = 0.05*(rand(length(x0),1)-0.5);
noise1 = interp1(x0,noise1,x);      % couse noise

noise2 = 0.005*(rand(n,1)-0.5);     % fine noise

y1 = smooth(y,100);                 % get the same trend
y1 = y1 + noise1 + noise2;          % modificated signal
plot(x,y,x,y1,'r')

[moncef soualhi]

Hi,

I wouldn't want to exaggerate, but please allow me, I have attached a file that better illustrates my problem.

I am infinitely grateful for your help.

[darova]

For moving ix Y direction you have to use function that has zero values at start/end

• 
• 
• 

For moving in X direction only start has to be zero

clc,clear
load data.mat
y = data';
n = length(y);
x = (1:n);

    % modificate data using x^2
xr = linspace(-1,1,length(x));
yr = -(xr.^2-1);                 % zero at the ends

subplot(411)
plot(x,y,  x,y-0.1*yr,'r')       % move data down

subplot(412)
plot(x,y,  x,y+0.1*yr,'r')       % move data up

    % modificate data using sin(x)
xr1 = linspace(0,pi,length(x));
yr1 = sin(xr1);                  % zero at the ends

subplot(413)
plot(x,y,  x,y-0.2*yr1,'r')

subplot(414)
plot(x,y,  x-100*yr1,y+0.2*yr1,'r')

[moncef soualhi]

Thank you for your help