From: RailGun09 hui on 24 Apr 2010 06:23 Hi people. I'm currently doing a project of getting the timing between 2 peaks. Hence i plan to go about it by getting the coordinates of each peak and i can then minus the corresponding X coordinates for the timing. I have tried using functions like 'findpeaks', 'max' and also 'peaks' but to no avail. I could only get the Y value from 'findpeaks' but not the X value. Hope that you people out there can help me. Thanks very much.
From: us on 24 Apr 2010 08:58 "RailGun09 hui" <zhizhehui(a)hotmail.com> wrote in message <hqugq9$aka$1(a)fred.mathworks.com>... > Hi people. I'm currently doing a project of getting the timing between 2 peaks. Hence i plan to go about it by getting the coordinates of each peak and i can then minus the corresponding X coordinates for the timing. > > I have tried using functions like 'findpeaks', 'max' and also 'peaks' but to no avail. I could only get the Y value from 'findpeaks' but not the X value. > > Hope that you people out there can help me. Thanks very much. one of the many solutions x=0:30:360; y=sind(x)+rand(size(x)); line(x,y,'marker','s'); [ym,ix]=find(sign(diff(y))==-1,1,'first'); % <- a very simple peak finder... line(x(ix),y(ix),'marker','s','markerfacecolor',[1,0,0]); us
From: RailGun09 on 24 Apr 2010 11:17 "us " <us(a)neurol.unizh.ch> wrote in message <hqupst$jo7$1(a)fred.mathworks.com>... > "RailGun09 hui" <zhizhehui(a)hotmail.com> wrote in message <hqugq9$aka$1(a)fred.mathworks.com>... > > Hi people. I'm currently doing a project of getting the timing between 2 peaks. Hence i plan to go about it by getting the coordinates of each peak and i can then minus the corresponding X coordinates for the timing. > > > > I have tried using functions like 'findpeaks', 'max' and also 'peaks' but to no avail. I could only get the Y value from 'findpeaks' but not the X value. > > > > Hope that you people out there can help me. Thanks very much. > > one of the many solutions > > x=0:30:360; > y=sind(x)+rand(size(x)); > line(x,y,'marker','s'); > [ym,ix]=find(sign(diff(y))==-1,1,'first'); % <- a very simple peak finder... > line(x(ix),y(ix),'marker','s','markerfacecolor',[1,0,0]); > > us Thanks for your help but I am not very sure how to implement your solution in my project. As what i would want would be to locate each peak's x and y coordinate. It would be better to explain clearer your solution as I'm still new to matlab so maybe i might have missed out something important here. And also for my project i'm using the plot function and you're using the line function. So will it affect what i want? Thanks.
From: us on 24 Apr 2010 11:37 "RailGun09 " <zhizhehui(a)hotmail.com> wrote in message <hqv21h$rpo$1(a)fred.mathworks.com>... > "us " <us(a)neurol.unizh.ch> wrote in message <hqupst$jo7$1(a)fred.mathworks.com>... > > "RailGun09 hui" <zhizhehui(a)hotmail.com> wrote in message <hqugq9$aka$1(a)fred.mathworks.com>... > > > Hi people. I'm currently doing a project of getting the timing between 2 peaks. Hence i plan to go about it by getting the coordinates of each peak and i can then minus the corresponding X coordinates for the timing. > > > > > > I have tried using functions like 'findpeaks', 'max' and also 'peaks' but to no avail. I could only get the Y value from 'findpeaks' but not the X value. > > > > > > Hope that you people out there can help me. Thanks very much. > > > > one of the many solutions > > > > x=0:30:360; > > y=sind(x)+rand(size(x)); > > line(x,y,'marker','s'); > > [ym,ix]=find(sign(diff(y))==-1,1,'first'); % <- a very simple peak finder... > > line(x(ix),y(ix),'marker','s','markerfacecolor',[1,0,0]); > > > > us > > Thanks for your help but I am not very sure how to implement your solution in my project. As what i would want would be to locate each peak's x and y coordinate. It would be better to explain clearer your solution as I'm still new to matlab so maybe i might have missed out something important here. And also for my project i'm using the plot function and you're using the line function. So will it affect what i want? Thanks. well... firstly, see help find; % to find out that the second output arg IX returns the position % where FIND found the condition - in this case: the YM, the value of the peak [ym,ix]=find(...condition=true...); % now, we use this linear index IX to retrieve the respective value in the array X line(x(ix),y(ix),...) % note: y(ix) <==> ym, but we use y(ix) for educational purposes... us
From: RailGun09 on 25 Apr 2010 02:28 "us " <us(a)neurol.unizh.ch> wrote in message <hqv374$cht$1(a)fred.mathworks.com>... > "RailGun09 " <zhizhehui(a)hotmail.com> wrote in message <hqv21h$rpo$1(a)fred.mathworks.com>... > > "us " <us(a)neurol.unizh.ch> wrote in message <hqupst$jo7$1(a)fred.mathworks.com>... > > > "RailGun09 hui" <zhizhehui(a)hotmail.com> wrote in message <hqugq9$aka$1(a)fred.mathworks.com>... > > > > Hi people. I'm currently doing a project of getting the timing between 2 peaks. Hence i plan to go about it by getting the coordinates of each peak and i can then minus the corresponding X coordinates for the timing. > > > > > > > > I have tried using functions like 'findpeaks', 'max' and also 'peaks' but to no avail. I could only get the Y value from 'findpeaks' but not the X value. > > > > > > > > Hope that you people out there can help me. Thanks very much. > > > > > > one of the many solutions > > > > > > x=0:30:360; > > > y=sind(x)+rand(size(x)); > > > line(x,y,'marker','s'); > > > [ym,ix]=find(sign(diff(y))==-1,1,'first'); % <- a very simple peak finder... > > > line(x(ix),y(ix),'marker','s','markerfacecolor',[1,0,0]); > > > > > > us > > > > Thanks for your help but I am not very sure how to implement your solution in my project. As what i would want would be to locate each peak's x and y coordinate. It would be better to explain clearer your solution as I'm still new to matlab so maybe i might have missed out something important here. And also for my project i'm using the plot function and you're using the line function. So will it affect what i want? Thanks. > > well... > > firstly, see > > help find; > > % to find out that the second output arg IX returns the position > % where FIND found the condition - in this case: the YM, the value of the peak > > [ym,ix]=find(...condition=true...); > > % now, we use this linear index IX to retrieve the respective value in the array X > > line(x(ix),y(ix),...) > > % note: y(ix) <==> ym, but we use y(ix) for educational purposes... > > us Hi, i understand that values that ym and ix give me is from the matrix itself. But what i would want are values from the respective axes itself. For example like for y axis would be a value of 356.456 and x would be a value of 0.567. Is it possible?
|
Next
|
Last
Pages: 1 2 Prev: foveal algoritm with matlab Next: HELP ME, Arrgh.. close(vid) on image acquisition |