Thread Subject:

Envelope curve of hysteresis plot

Hello,

I have a plot of x and y values in form of hysteresis curve. Is it possible to extract the positive and negative envelope from such curve with a routine in Matlab?

Thanks in advance,
medo_sk

"medo_sk Churilov" <curilov@gf.ukim.edu.mk> wrote in message <idli1t$hde$1@fred.mathworks.com>...
> Hello,
>
> I have a plot of x and y values in form of hysteresis curve. Is it possible to extract the positive and negative envelope from such curve with a routine in Matlab?
>
> Thanks in advance,
> medo_sk

Please see the engine in the last post in this thread:
http://www.mathworks.com/matlabcentral/newsreader/view_thread/296817

"Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <idlimh$199$1@fred.mathworks.com>...
> "medo_sk Churilov" <curilov@gf.ukim.edu.mk> wrote in message <idli1t$hde$1@fred.mathworks.com>...
> > Hello,
> >
> > I have a plot of x and y values in form of hysteresis curve. Is it possible to extract the positive and negative envelope from such curve with a routine in Matlab?
> >
> > Thanks in advance,
> > medo_sk
>
> Please see the engine in the last post in this thread:
> http://www.mathworks.com/matlabcentral/newsreader/view_thread/296817



Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?

"Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <idlimh$199$1@fred.mathworks.com>...
> "medo_sk Churilov" <curilov@gf.ukim.edu.mk> wrote in message <idli1t$hde$1@fred.mathworks.com>...
> > Hello,
> >
> > I have a plot of x and y values in form of hysteresis curve. Is it possible to extract the positive and negative envelope from such curve with a routine in Matlab?
> >
> > Thanks in advance,
> > medo_sk
>
> Please see the engine in the last post in this thread:
> http://www.mathworks.com/matlabcentral/newsreader/view_thread/296817



Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?

> Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?

Show us your data...

"Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido7hh$ggi$1@fred.mathworks.com>...
>
> > Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?
>
> Show us your data...

Here is the data saved in m.file. Column 1 contains values for y axis, while column 2 has values for x-axis.
http://www.4shared.com/file/RfUZPdYZ/hysteresis.html

"medo_sk " <curilov@gf.ukim.edu.mk> wrote in message <ido90b$nsk$1@fred.mathworks.com>...
> "Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido7hh$ggi$1@fred.mathworks.com>...
> >
> > > Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?
> >
> > Show us your data...
>
> Here is the data saved in m.file. Column 1 contains values for y axis, while column 2 has values for x-axis.
> http://www.4shared.com/file/RfUZPdYZ/hysteresis.html

Is this what you want:
x = hysteresisCopy(:,1);
y = hysteresisCopy(:,2);
k = convhull(x,y);
plot(x(k),y(k),'r-',x,y,'b--')

"Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido9sg$oeu$1@fred.mathworks.com>...
> "medo_sk " <curilov@gf.ukim.edu.mk> wrote in message <ido90b$nsk$1@fred.mathworks.com>...
> > "Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido7hh$ggi$1@fred.mathworks.com>...
> > >
> > > > Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?
> > >
> > > Show us your data...
> >
> > Here is the data saved in m.file. Column 1 contains values for y axis, while column 2 has values for x-axis.
> > http://www.4shared.com/file/RfUZPdYZ/hysteresis.html
>
> Is this what you want:
> x = hysteresisCopy(:,1);
> y = hysteresisCopy(:,2);
> k = convhull(x,y);
> plot(x(k),y(k),'r-',x,y,'b--')

No, I did try 'convhull' also, but it is not what I want.
Please check the following link to see shat I need to plot.
http://www.4shared.com/photo/sP7qtXyo/env.html
The solid bold line is the envelope with both positive and negative part of the diagram. The hysteresis from some other data is plotted in gray.

"medo_sk " <curilov@gf.ukim.edu.mk> wrote in message <idq34c$a0$1@fred.mathworks.com>...
> "Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido9sg$oeu$1@fred.mathworks.com>...
> > "medo_sk " <curilov@gf.ukim.edu.mk> wrote in message <ido90b$nsk$1@fred.mathworks.com>...
> > > "Sean de " <sean.dewolski@nospamplease.umit.maine.edu> wrote in message <ido7hh$ggi$1@fred.mathworks.com>...
> > > >
> > > > > Nope, this is not want I want. I want to plot envelope curve from data set points of x and y axis. Any suggestion?
> > > >
> > > > Show us your data...
> > >
> > > Here is the data saved in m.file. Column 1 contains values for y axis, while column 2 has values for x-axis.
> > > http://www.4shared.com/file/RfUZPdYZ/hysteresis.html
> >
> > Is this what you want:
> > x = hysteresisCopy(:,1);
> > y = hysteresisCopy(:,2);
> > k = convhull(x,y);
> > plot(x(k),y(k),'r-',x,y,'b--')
>
> No, I did try 'convhull' also, but it is not what I want.
> Please check the following link to see shat I need to plot.
> http://www.4shared.com/photo/sP7qtXyo/env.html
> The solid bold line is the envelope with both positive and negative part of the diagram. The hysteresis from some other data is plotted in gray.

Does anyone has an idea for this problem?

On pon, 13 gru 2010 14:37:05 in article news:<ie57i1$8dm$1@fred.mathworks.com>
medo_sk wrote:
>> No, I did try 'convhull' also, but it is not what I want.
>> Please check the following link to see shat I need to plot.
>> http://www.4shared.com/photo/sP7qtXyo/env.html
>> The solid bold line is the envelope with both positive and negative part of the diagram. The hysteresis from some other data is plotted in gray.
>
> Does anyone has an idea for this problem?

This is what you need?

load hysteresis.mat

x=hysteresisCopy(:,2);
y=hysteresisCopy(:,1);

x1=x/std(x);
y1=y/std(y);
z=(x1.^2+y1.^2).^.5;

% look for min peak
plot(z);
pause;

M=0.4; % min peak
i=2:length(z)-1;
j=i(find( z(i-1)<z(i) & z(i)>z(i+1) & z(i)>M ));

% delete spurious peaks
i=1;
while i<length(j);
  if z(j(i))/2>z(j(i+1)); j(i+1)=[]; else i=i+1; end;
end

% check results
plot(z,'-',j,z(j),'r+')
pause

[i,i]=sort(x(j));
js=j(i);

% final envelope
plot(x,y,'c',x(js),y(js),'r*-')