blur=0 gets ignored in AP?

AFNI Message Board
1

AFNI version info (afni -ver):
Precompiled binary macos_13_ARM: Sep 1 2025 (Version AFNI_25.2.09 'Gordian I')

it seems to me that if one has "-blur_size 0" in afni_proc, this gets ignored and the default of 4mm fwhm is used. i think even 0.0 gets ignored, rather i have to put something like 0.00000001 and then i get effectively no blurring. was this maybe fixed after Sep 1 with those blur_size edits i see in the afni history? was hoping not to have to update now but i can. thanks!

-sam

2

Ciao-

Indeed, the guts of db_mod.py do check for a blur_size value being specifically bigger than 0 to accept it (see line 8 here), otherwise it will go with a default value:

def db_cmd_blur(proc, block):

    # first get blur size, then possibly handle surface case
    val, err = proc.user_opts.get_type_opt(float, '-blur_size')
    if err:
        print('** error: -blur_size requires float argument')
        return 1
    elif val is not None and val > 0.0:
        size = val
        havesize = 1
    else:
        dsize = 4.0
        size = UTIL.get_def_blur_from_dims(proc.dsets[0].nice_input())
        mesg = "** no -blur_size: using old default of %g" % dsize
        if size > 0.0 and size != dsize:
           mesg += ", but consider new default of %g\n" % size
        mesg += "   (preferably, specify -blur_size directly)"
        print(mesg)

        # stick with current default
        size = dsize
        havesize = 0

If blurring is not wanted, then the blur block should not be included in the processing.

I will guess that this situation might have arisen because you have an if-condition or something when setting up AP across a group, so some data gets a blur and other doesn't? If that is the case, you can include the list of blocks being used along with that. E.g., in shell script:

if ( $DO_BLUR ) then
   set blur_size  = 4.57
   set blur_opt   = "-blur_size ${blur_size}"
   set block_list = ( shift align tlrc volreg mask blur scale regress )
else
   set blur_opt   = ""
   set block_list = ( shift align tlrc volreg mask  scale regress )
endif

--pt

3

thanks for the fast reply! ya know what, i was building this AP off an older one. i think i was having errors that made me think i needed a blur block. anyway, you're right, i just tested it without and i can just leave it out, sheesh. sorry!