Dear Greg,
Thanks for your advice, it does work :-). Just let me add two
pieces of information in case somebody is in the same situation I was.
---
there is a small error in the dx file, it says
delta 0.5 0.5 0
delta 0.5 0.5 0
delta 0 0.5 0.5
when the correct one is:
delta 0.5 0.5 0
delta 0.5 0.0 0.5
delta 0 0.5 0.5
-------
asuming the file containing the volume is called filename.vol and that
there is a float per voxel the command
tail -c Nbytes filename.vol | od -vf | cut -b 10-80 > test.data
will convert the last Nbytes of the file filename.vol in an ascii file
called test.data ready for dx
best wishes
Roberto
On Wed, 10 Oct 2001, Gregory D Abram wrote:
>
> Easiest way, IMHO, is to forgo the general array importer format and use
> the standard OpenDX format. I figured out the correct syntax by creating a
> fake data set in OpenDX and exporting it, using options to specify that the
> output be placed in two separate files, one containing the header and the
> other the data, and to make the data file ascii, rather than binary. I did
> it in script mode, for a 9x9x9 array rather than 90x90x90 (I'm low on disk
> space)
>
> dx -script
>
> a = Construct([0 0 0], {[0.5 0.5 0.0][0.5 0.5 0.0][0.0 0.5 0.5]}, [9 9 9], {
> 1.0 .. 729 });
> a = Compute("$0", a);
> Export(a, "test", "dx ascii 2");
>
> (the compute is so that the data file contained something other than a
> regular array).
>
> The result, in test.dx, is
> object 1 class gridpositions counts 9 9 9
> origin 0 0 0
> delta 0.5 0.5 0
> delta 0.5 0.5 0
> delta 0 0.5 0.5
> attribute "dep" string "positions"
> #
> object 2 class gridconnections counts 9 9 9
> attribute "element type" string "cubes"
> attribute "dep" string "connections"
> attribute "ref" string "positions"
> #
> object 3 class array type float rank 1 shape 1 items 729 data file test.data,0
> attribute "dep" string "positions"
> #
> object "default" class field
> component "positions" value 1
> component "connections" value 2
> component "data" value 3
> #
> end
>
> And test.data simply contains 729 ascii floats. If I hadn't specified
> 'ascii', then test.data would have contained 729 binary floats.
>
> Greg
>
> Please respond to [email protected]
>
> Sent by: [EMAIL PROTECTED]
>
>
> To: [email protected]
> cc:
> Subject: [opendx-users] Importing data in a FCC grid
>
>
>
>
> Dear all,
>
>
> I use opendx for visualizing volumes, up today these volumes where
> described by a single file composed by a header and an array of
> floats. For importing the data I use "headers files" like:
>
> -------------------
> file =spher.fcc
> grid = 90 x 90 x 90
> #linux
> format = lsb ieee
> #sgi
> #format = msb ieee
> interleaving = record
> majority = column
> header = bytes 1296
> field = Density
> structure = scalar
> type = float
> dependency = positions
> #positions = -45, 1, -45, 1, -45, 1
> positions = 0, 1, 0, 1, 0, 1
>
> end
> ----------------
>
> These volumes are sampled using a cubic grid with sampling rate 1, or what
> is the same using the opendx vocabulary the deltas are:
>
> delta 1 0 0
> delta 0 1.0 0
> delta 0 0 1.0
>
> Now I need to visualize volumes recorded using
>
> delta 0.5 0.5 0
> delta 0.5 0.0 0.5
> delta 0.0 0.5 0.5
>
>
> How should I change the header file? My guess is that the field
> "positions" is the one that need to be modified but how?
>
> thanks for the help
>
>
> Roberto
>
>
>
>
>
