Does the Radon transform work with NaNs?
in [Matlab]
|
From: Freja Hunt on 20 May 2010 10:34 "Matt J " <mattjacREMOVE(a)THISieee.spam> wrote in message <ht3gk9$s5v$1(a)fred.mathworks.com>... > "Freja Hunt" <pinkfridgee(a)hotmail.co.uk> wrote in message <ht3fm9$nho$1(a)fred.mathworks.com>... > > > Yes I guess after doing the means I could re-convert the NaNs back to noughts to apply the transform then convert them back to NaNs for further processing later in the code, but I was hoping to avoid all that extra fiddling. > =============== > > I think you're overestimating the work it requires. These are 1-line conversions > > NanMap=isnan(data); %precompute the map of nans > > data(NanMap)=0; %convert to zeros; > > data(NanMap)=nan; %convert back to nans Ah thankyou that is a much more compact conversion than I was using! Thanks for the help. Do you know whether the inclusion of extra units effects the outcome of the integral in the same way as it does with means?
From: Matt J on 20 May 2010 10:42 "Freja Hunt" <pinkfridgee(a)hotmail.co.uk> wrote in message <ht3h8s$bon$1(a)fred.mathworks.com>... > > Do you know whether the inclusion of extra units effects the outcome of the integral in the same way as it does with means? No, it doesn't, other than perhaps requiring a larger sized grid to hold the results. But that's only the case if the "extra units" enlarge the footprint of the image.
From: Freja Hunt on 20 May 2010 10:48
"Matt J " <mattjacREMOVE(a)THISieee.spam> wrote in message <ht3hnu$dai$1(a)fred.mathworks.com>... > "Freja Hunt" <pinkfridgee(a)hotmail.co.uk> wrote in message <ht3h8s$bon$1(a)fred.mathworks.com>... > > > > > Do you know whether the inclusion of extra units effects the outcome of the integral in the same way as it does with means? > > No, it doesn't, other than perhaps requiring a larger sized grid to hold the results. But that's only the case if the "extra units" enlarge the footprint of the image. Thats great, thanks so much for your help. Freja |