MATLAB: How to use spline for a fig. file

spline on figure

Can I use spline to smooth the plot in attached file?

Best Answer

Try this:

I = openfig('fft scma 25.fig');
Ax = gca;
lgnd = Ax.Legend;
Lines = findobj(Ax,'Type','line');
N = 5;                                                              % Interpolation Points Length Multiplication
for k = 1:numel(Lines)
    X(k,:) = Lines(k).XData;
    Y(k,:) = Lines(k).YData;
    xq(k,:) = linspace(min(X(k,:)),max(X(k,:)), numel(X(k,:))*N);   % Interpolation Points Vector
    ys(k,:) = spline(X(k,:),Y(k,:),xq(k,:));                        % Spline Fit To Data
end
figure
semilogy(xq', ys')
grid
legend(Ax.Legend.String)
xlabel(Ax.XLabel.String)
ylabel(Ax.YLabel.String)

Change ‘N’ to get the result you want.

This is essentially the same as my previous code, this time doing a spline interpolation.

EDIT —

Corrected typographical error. Code unchanged.

Related Solutions

MATLAB: How to make a plot smooth

It depends on what you intend by ’smooth’.

Try this:

I = openfig('scma25.fig');
Ax = gca;
Lines = findobj(Ax,'Type','line');
for k = 1:numel(Lines)
    X(k,:) = Lines(k).XData;
    Y(k,:) = Lines(k).YData;
    pv(:,k) = polyfit(X(k,:), Y(k,:), 3);
    yf(k,:) = polyval(pv(:,k),X(k,:));
end
figure
semilogy(X', yf')
grid
legend(Ax.Legend.String)
xlabel(Ax.XLabel.String)
ylabel(Ax.YLabel.String)

It uses polyfit and polyval to fit your data, then plots the fitted data in a new figure. It also re-uses your axis labels and legend strings.

MATLAB: I have five figure in .Fig extension which i am creating after plotting 5 rows from a dataset. Now i want to Join these 5 figure into one figure in vertical allignemnt

for each .fig, use openfig() to open the figure and return a handle to it. For each of those handles, h(K)

h_line = findobj(h(K), 'type', 'line');
line_ax = ancestor(h_line, 'axes');
title_obj = get(line_ax, 'title');
titles{K} = get(title_obj, 'string');
xlab{K} = get(line_ax, 'xlabel');
ylab{K} = get(line_ax, 'ylabel');
xdata{K} = get(h_line, 'xdata');
ydata{K} = get(h_line, 'ydata');

Once you have all of those, you can create a new figure and

for K = 1 : 5
  ax = subplot(5,1,K);
  plot(xdata{K}, ydata{K});
  title(titles{K});
  xlabel(xlab{K});
  ylabel(ylab{K});
end

You can extend this if you need the tick marks to be specifically copied instead of automatically generated, or need special font, and so on.

Best Answer

Related Solutions

MATLAB: How to make a plot smooth

MATLAB: I have five figure in .Fig extension which i am creating after plotting 5 rows from a dataset. Now i want to Join these 5 figure into one figure in vertical allignemnt

Related Question