hi everybody how can I collect many vectors in one matrix EX:
I1 = [ 2 3 4 5 2 ]I2 = [ 6 5 4 3 2]I3 = [ 9 8 7 6 5 ]The answer waht i want
G = [ 2 3 4 5 2;6 5 4 3 2; 9 8 7 6 5 ].Thank you
MATLAB: Collection many vectors in one matrix
matrix manipulation
Related Solutions
Use this FEX
load data.mat % attached above
ydata(end) = []; % your xdata/ydata do not match in length !
slope0 = struct('p', 1, 'x', [min(xdata) max(xdata)], 'v', [0 0]);% Download BSFK function here
% https://www.mathworks.com/matlabcentral/fileexchange/25872-free-knot-spline-approximation
pp = BSFK(xdata,ydata, 2, 3, [], struct('KnotRemoval', 'none', 'pntcon', slope0)); % Check
figurexi = linspace(min(xdata),max(xdata));yi = ppval(pp,xi)plot(xdata,ydata,'b',xi,yi,'r');for xb=pp.breaks xline(xb);endgrid on
hello
see example below
this could be interesting for data 1 example
but the two other data it's not feasible unless someone come's with a clever condtion equation to select such fraction of data
[num,txt,raw] = xlsread('Data 1.xlsx') ; time = num(:,1); % s
current = num(:,2); % A
voltage = num(:,3); % V
samples = length(time); dt = (time(end)-time(1))/(samples-1); Fs = 1/dt; % main loop : extract min max vales for every 5 min data %
[dvoltage, ddvoltage] = firstsecondderivatives(time,voltage);figure(1);subplot(2,1,1),plot(time,voltage,'-b');gridsubplot(2,1,2),plot(time,dvoltage,'-b');grid% selected buffer is defined between the two positive peaks of dvoltage
dvoltage_max = max(dvoltage(dvoltage>0));threshold = dvoltage_max/2;ind = find(dvoltage > threshold);ind_start = ind(1)-100;ind_stop = ind(end)-100;% plot selected portion of data
figure(2);plot(time,voltage,'-b',time(ind_start:ind_stop),voltage(ind_start:ind_stop),'or');gridfunction [dy, ddy] = firstsecondderivatives(x,y)% The function calculates the first & second derivative of a function that is given by a set
% of points. The first derivatives at the first and last points are calculated by
% the 3 point forward and 3 point backward finite difference scheme respectively.
% The first derivatives at all the other points are calculated by the 2 point
% central approach.
% The second derivatives at the first and last points are calculated by
% the 4 point forward and 4 point backward finite difference scheme respectively.
% The second derivatives at all the other points are calculated by the 3 point
% central approach.n = length (x);dy = zeros;ddy = zeros;% Input variables:
% x: vector with the x the data points.
% y: vector with the f(x) data points.
% Output variable:
% dy: Vector with first derivative at each point.
% ddy: Vector with second derivative at each point.
dy(1) = (-3*y(1) + 4*y(2) - y(3)) / 2*(x(2) - x(1)); % First derivative
ddy(1) = (2*y(1) - 5*y(2) + 4*y(3) - y(4)) / (x(2) - x(1))^2; % Second derivative
for i = 2:n-1 dy(i) = (y(i+1) - y(i-1)) / 2*(x(i+1) - x(i-1));ddy(i) = (y(i-1) - 2*y(i) + y(i+1)) / (x(i-1) - x(i))^2;enddy(n) = (y(n-2) - 4*y(n-1) + 3*y(n)) / 2*(x(n) - x(n-1));ddy(n) = (-y(n-3) + 4*y(n-2) - 5*y(n-1) + 2*y(n)) / (x(n) - x(n-1))^2;end
Best Answer