Hi Doug - that's right - thanks Krish. Note also that you can have both
commands in one:
avwmaths_32R phase0 -sub 2047.5 -mul 0.00153436 phase2
On Fri, 23 Jul 2004, Dr Krish Singh wrote:
> Hi Doug,
> I'm not an expert, but I think if you use avwmaths_32R (instead of avwmaths)
> it will force your output to be a float instead of a short int. avwmaths_64R
> will output a double float.
> Hope that's right!
> On 23/7/04 9:31 pm, "Doug Greve" <[log in to unmask]> wrote:
> > Is there a way to change the precision of an analyze file? It would be
> > nice if avwmaths could do it, when rescaling for example. My problem is
> > that I need to rescale a B0 phase map. The DICOM for this has short
> > precision and ranges from 0-4095, so here's what I'm doing:
> > avwmaths phase0.hdr -sub 2047.5 phase1.hdr
> > avwmaths phase1.hdr -mul 0.00153436 phase2.hdr
> > The problem is that each output stays as a short, so the resulting phase
> > map (phase2.hdr) is truncated and only has values of -3,-2,-1,0,2,1,3.
> > thanks
> > doug
> > --
> > Douglas N. Greve, Ph.D.
> > MGH-NMR Center
> > [log in to unmask]
> > Phone Number: 617-724-2358
> > Fax: 617-726-7422
> Dr K.D. Singh
> Senior Lecturer and Convenor of the Neuroimaging Research Group,
> Director, MRI Research Centre,
> Neurosciences Research Institute
> Aston University, Birmingham B4 7ET, U.K.
> Tel/Fax: +44 (0)121 [204 3865/3864]/[333 4220]
> [log in to unmask], http://www.aston.ac.uk/lhs/staff/singhkd/
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve