Python api.save_image函数代码示例

def test_save3():
    # A test to ensure that when a file is saved, the affine
    # and the data agree. In this case, things don't agree:
    # i) the pixdim is off
    # ii) makes the affine off
    step = np.array([3.45,2.3,4.5,6.9])
    shape = (13,5,7,3)
    mni_xyz = mni_csm(3).coord_names
    cmap = AT(CS('jkli'),
              CS(('t',) + mni_xyz[::-1]),
              from_matvec(np.diag([0,3,5,1]), step))
    data = np.random.standard_normal(shape)
    img = api.Image(data, cmap)
    # with InTemporaryDirectory():
    with InTemporaryDirectory():
        save_image(img, TMP_FNAME)
        tmp = load_image(TMP_FNAME)
        # Detach image from file so we can delete it
        data = tmp.get_data().copy()
        img2 = api.Image(data, tmp.coordmap, tmp.metadata)
        del tmp
    assert_equal(tuple([img.shape[l] for l in [3,2,1,0]]), img2.shape)
    a = np.transpose(np.asarray(img), [3,2,1,0])
    assert_false(np.allclose(img.affine, img2.affine))
    assert_true(np.allclose(a, img2.get_data()))

def test_save2b():
    # A test to ensure that when a file is saved, the affine and the
    # data agree. This image comes from a NIFTI file This example has
    # a non-diagonal affine matrix for the spatial part, but is
    # 'diagonal' for the space part.  this should raise a warnings
    # about 'non-diagonal' affine matrix

    # make a 5x5 transformatio
    step = np.array([3.45,2.3,4.5,6.9])
    A = np.random.standard_normal((4,4))
    B = np.diag(list(step)+[1])
    B[:4,:4] = A

    shape = (13,5,7,3)
    cmap = api.AffineTransform.from_params('ijkt', 'xyzt', B)

    data = np.random.standard_normal(shape)

    img = api.Image(data, cmap)

    save_image(img, tmpfile.name)
    img2 = load_image(tmpfile.name)
    yield assert_false, np.allclose(img.affine, img2.affine)
    yield assert_true, np.allclose(img.affine[:3,:3], img2.affine[:3,:3])
    yield assert_equal, img.shape, img2.shape
    yield assert_true, np.allclose(np.asarray(img2), np.asarray(img))

def group_analysis(design, contrast):
    """ Compute group analysis effect, t, sd for `design` and `contrast`

    Saves to disk in 'group' analysis directory

    Parameters
    ----------
    design : {'block', 'event'}
    contrast : str
        contrast name
    """
    array = np.array # shorthand
    # Directory where output will be written
    odir = futil.ensure_dir(futil.DATADIR, 'group', design, contrast)

    # Which subjects have this (contrast, design) pair?
    subj_con_dirs = futil.subj_des_con_dirs(design, contrast)
    if len(subj_con_dirs) == 0:
        raise ValueError('No subjects for %s, %s' % (design, contrast))

    # Assemble effects and sds into 4D arrays
    sds = []
    Ys = []
    for s in subj_con_dirs:
        sd_img = load_image(pjoin(s, "sd.nii"))
        effect_img = load_image(pjoin(s, "effect.nii"))
        sds.append(sd_img.get_data())
        Ys.append(effect_img.get_data())
    sd = array(sds)
    Y = array(Ys)

    # This function estimates the ratio of the fixed effects variance
    # (sum(1/sd**2, 0)) to the estimated random effects variance
    # (sum(1/(sd+rvar)**2, 0)) where rvar is the random effects variance.

    # The EM algorithm used is described in:
    #
    # Worsley, K.J., Liao, C., Aston, J., Petre, V., Duncan, G.H.,
    #    Morales, F., Evans, A.C. (2002). \'A general statistical
    #    analysis for fMRI data\'. NeuroImage, 15:1-15
    varest = onesample.estimate_varatio(Y, sd)
    random_var = varest['random']

    # XXX - if we have a smoother, use
    # random_var = varest['fixed'] * smooth(varest['ratio'])

    # Having estimated the random effects variance (and possibly smoothed it),
    # the corresponding estimate of the effect and its variance is computed and
    # saved.

    # This is the coordmap we will use
    coordmap = futil.load_image_fiac("fiac_00","wanatomical.nii").coordmap

    adjusted_var = sd**2 + random_var
    adjusted_sd = np.sqrt(adjusted_var)

    results = onesample.estimate_mean(Y, adjusted_sd) 
    for n in ['effect', 'sd', 't']:
        im = api.Image(results[n], copy(coordmap))
        save_image(im, pjoin(odir, "%s.nii" % n))

 def save(self):
     """
     Save current Image data to disk
     """
     if not self.clobber and path.exists(self.filename):
         raise ValueError('trying to clobber existing file')
     save_image(self._im, self.filename)
     self._flushed = True
     del(self._im)

def test_save1():
    # A test to ensure that when a file is saved, the affine and the
    # data agree. This image comes from a NIFTI file

    img = load_image(funcfile)
    save_image(img, tmpfile.name)
    img2 = load_image(tmpfile.name)
    yield assert_true, np.allclose(img.affine, img2.affine)
    yield assert_equal, img.shape, img2.shape
    yield assert_true, np.allclose(np.asarray(img2), np.asarray(img))

def test_save1():
    # A test to ensure that when a file is saved, the affine and the
    # data agree. This image comes from a NIFTI file
    img = load_image(funcfile)
    with InTemporaryDirectory():
        save_image(img, TMP_FNAME)
        img2 = load_image(TMP_FNAME)
        assert_array_almost_equal(img.affine, img2.affine)
        assert_equal(img.shape, img2.shape)
        assert_array_almost_equal(img2.get_data(), img.get_data())
        del img2

def fixed_effects(subj, design):
    """ Fixed effects (within subject) for FIAC model

    Finds run by run estimated model results, creates fixed effects results
    image per subject.

    Parameters
    ----------
    subj : int
        subject number 1..6 inclusive
    design : {'standard'}
        design type
    """
    # First, find all the effect and standard deviation images
    # for the subject and this design type
    path_dict = futil.path_info_design(subj, design)
    rootdir = path_dict['rootdir']
    # The output directory
    fixdir = pjoin(rootdir, "fixed")
    # Fetch results images from run estimations
    results = futil.results_table(path_dict)
    # Get our hands on the relevant coordmap to save our results
    coordmap = futil.load_image_fiac("_%02d" % subj,
                                     "wanatomical.nii").coordmap
    # Compute the "fixed" effects for each type of contrast
    for con in results:
        fixed_effect = 0
        fixed_var = 0
        for effect, sd in results[con]:
            effect = load_image(effect).get_data()
            sd = load_image(sd).get_data()
            var = sd ** 2

            # The optimal, in terms of minimum variance, combination of the
            # effects has weights 1 / var
            #
            # XXX regions with 0 variance are set to 0
            # XXX do we want this or np.nan?
            ivar = np.nan_to_num(1. / var)
            fixed_effect += effect * ivar
            fixed_var += ivar

        # Now, compute the fixed effects variance and t statistic
        fixed_sd = np.sqrt(fixed_var)
        isd = np.nan_to_num(1. / fixed_sd)
        fixed_t = fixed_effect * isd

        # Save the results
        odir = futil.ensure_dir(fixdir, con)
        for a, n in zip([fixed_effect, fixed_sd, fixed_t],
                        ['effect', 'sd', 't']):
            im = api.Image(a, copy(coordmap))
            save_image(im, pjoin(odir, '%s.nii' % n))

def test_write():
    fname = "myfile.nii"
    img = load_image(funcfile)
    with InTemporaryDirectory():
        save_image(img, fname)
        test = FmriImageList.from_image(load_image(fname))
        assert_equal(test[0].affine.shape, (4, 4))
        assert_equal(img[0].affine.shape, (5, 4))
        # Check the affine...
        A = np.identity(4)
        A[:3, :3] = img[:, :, :, 0].affine[:3, :3]
        A[:3, -1] = img[:, :, :, 0].affine[:3, -1]
        assert_true(np.allclose(test[0].affine, A))
        del test

def test_space_time_realign():
    path, fname = psplit(funcfile)
    original_affine = load_image(funcfile).affine
    path, fname = psplit(funcfile)
    froot, _ = fname.split('.', 1)
    with InTemporaryDirectory():
        # Make another image with .nii extension and extra dot in filename
        save_image(load_image(funcfile), 'my.test.nii')
        for in_fname, out_fname in ((funcfile, froot + '_mc.nii.gz'),
                                    ('my.test.nii', 'my.test_mc.nii.gz')):
            xforms = reg.space_time_realign(in_fname, 2.0, out_name='.')
            assert_true(np.allclose(xforms[0].as_affine(), np.eye(4), atol=1e-7))
            assert_false(np.allclose(xforms[-1].as_affine(), np.eye(4), atol=1e-3))
            img = load_image(out_fname)
            npt.assert_almost_equal(original_affine, img.affine)

def test_save2():
    # A test to ensure that when a file is saved, the affine and the
    # data agree. This image comes from a NIFTI file 
    shape = (13,5,7,3)
    step = np.array([3.45,2.3,4.5,6.93])
    cmap = api.AffineTransform.from_start_step('ijkt', 'xyzt', [1,3,5,0], step)
    data = np.random.standard_normal(shape)
    img = api.Image(data, cmap)
    with InTemporaryDirectory():
        save_image(img, TMP_FNAME)
        img2 = load_image(TMP_FNAME)
        assert_array_almost_equal(img.affine, img2.affine)
        assert_equal(img.shape, img2.shape)
        assert_array_almost_equal(img2.get_data(), img.get_data())
        del img2

def fixed_effects(subj, design):
    """
    Fixed effects (within subject) for FIAC model
    """

    # First, find all the effect and standard deviation images
    # for the subject and this design type

    path_dict = futil.path_info2(subj, design)
    rootdir = path_dict['rootdir']
    # The output directory
    fixdir = pjoin(rootdir, "fixed")

    results = futil.results_table(path_dict)

    # Get our hands on the relevant coordmap to
    # save our results
    coordmap = futil.load_image_fiac("fiac_%02d" % subj,
                                     "wanatomical.nii").coordmap

    # Compute the "fixed" effects for each type of contrast
    for con in results:
        fixed_effect = 0
        fixed_var = 0
        for effect, sd in results[con]:
            effect = load_image(effect); sd = load_image(sd)
            var = np.array(sd)**2

            # The optimal, in terms of minimum variance, combination of the
            # effects has weights 1 / var
            #
            # XXX regions with 0 variance are set to 0
            # XXX do we want this or np.nan?
            ivar = np.nan_to_num(1. / var)
            fixed_effect += effect * ivar
            fixed_var += ivar

        # Now, compute the fixed effects variance and t statistic
        fixed_sd = np.sqrt(fixed_var)
        isd = np.nan_to_num(1. / fixed_sd)
        fixed_t = fixed_effect * isd

        # Save the results
        odir = futil.ensure_dir(fixdir, con)
        for a, n in zip([fixed_effect, fixed_sd, fixed_t],
                        ['effect', 'sd', 't']):
            im = api.Image(a, coordmap.copy())
            save_image(im, pjoin(odir, '%s.nii' % n))

def group_analysis(design, contrast):
    """
    Compute group analysis effect, sd and t
    for a given contrast and design type
    """
    array = np.array # shorthand
    # Directory where output will be written
    odir = futil.ensure_dir(futil.DATADIR, 'group', design, contrast)

    # Which subjects have this (contrast, design) pair?
    subjects = futil.subject_dirs(design, contrast)

    sd = array([array(load_image(pjoin(s, "sd.nii"))) for s in subjects])
    Y = array([array(load_image(pjoin(s, "effect.nii"))) for s in subjects])

    # This function estimates the ratio of the
    # fixed effects variance (sum(1/sd**2, 0))
    # to the estimated random effects variance
    # (sum(1/(sd+rvar)**2, 0)) where
    # rvar is the random effects variance.

    # The EM algorithm used is described in 
    #
    # Worsley, K.J., Liao, C., Aston, J., Petre, V., Duncan, G.H., 
    #    Morales, F., Evans, A.C. (2002). \'A general statistical 
    #    analysis for fMRI data\'. NeuroImage, 15:1-15

    varest = onesample.estimate_varatio(Y, sd)
    random_var = varest['random']

    # XXX - if we have a smoother, use
    # random_var = varest['fixed'] * smooth(varest['ratio'])

    # Having estimated the random effects variance (and
    # possibly smoothed it), the corresponding
    # estimate of the effect and its variance is
    # computed and saved.

    # This is the coordmap we will use
    coordmap = futil.load_image_fiac("fiac_00","wanatomical.nii").coordmap

    adjusted_var = sd**2 + random_var
    adjusted_sd = np.sqrt(adjusted_var)

    results = onesample.estimate_mean(Y, adjusted_sd) 
    for n in ['effect', 'sd', 't']:
        im = api.Image(results[n], coordmap.copy())
        save_image(im, pjoin(odir, "%s.nii" % n))

def test_save2():
    # A test to ensure that when a file is saved, the affine and the
    # data agree. This image comes from a NIFTI file 

    shape = (13,5,7,3)
    step = np.array([3.45,2.3,4.5,6.93])

    cmap = api.AffineTransform.from_start_step('ijkt', 'xyzt', [1,3,5,0], step)

    data = np.random.standard_normal(shape)
    img = api.Image(data, cmap)
    save_image(img, tmpfile.name)
    img2 = load_image(tmpfile.name)
    yield assert_true, np.allclose(img.affine, img2.affine)
    yield assert_equal, img.shape, img2.shape
    yield assert_true, np.allclose(np.asarray(img2), np.asarray(img))

def test_save4():
    # Same as test_save3 except we have reordered the 'ijk' input axes.
    shape = (13,5,7,3)
    step = np.array([3.45,2.3,4.5,6.9])
    # When the input coords are in the 'ljki' order, the affines get
    # rearranged.  Note that the 'start' below, must be 0 for
    # non-spatial dimensions, because we have no way to store them in
    # most cases.  For example, a 'start' of [1,5,3,1] would be lost on
    # reload
    mni_xyz = mni_csm(3).coord_names
    cmap = AT(CS('tkji'),
              CS((('t',) + mni_xyz[::-1])),
              from_matvec(np.diag([2., 3, 5, 1]), step))
    data = np.random.standard_normal(shape)
    img = api.Image(data, cmap)
    with InTemporaryDirectory():
        save_image(img, TMP_FNAME)
        tmp = load_image(TMP_FNAME)
        data = tmp.get_data().copy()
        # Detach image from file so we can delete it
        img2 = api.Image(data, tmp.coordmap, tmp.metadata)
        del tmp
    P = np.array([[0,0,0,1,0],
                  [0,0,1,0,0],
                  [0,1,0,0,0],
                  [1,0,0,0,0],
                  [0,0,0,0,1]])
    res = np.dot(P, np.dot(img.affine, P.T))
    # the step part of the affine should be set correctly
    assert_array_almost_equal(res[:4,:4], img2.affine[:4,:4])
    # start in the spatial dimensions should be set correctly
    assert_array_almost_equal(res[:3,-1], img2.affine[:3,-1])
    # start in the time dimension should be 3.45 as in img, because NIFTI stores
    # the time offset in hdr[``toffset``]
    assert_not_equal(res[3,-1], img2.affine[3,-1])
    assert_equal(res[3,-1], 3.45)
    # shapes should be reversed because img has coordinates reversed
    assert_equal(img.shape[::-1], img2.shape)
    # data should be transposed because coordinates are reversed
    assert_array_almost_equal(
           np.transpose(np.asarray(img2),[3,2,1,0]),
           np.asarray(img))
    # coordinate names should be reversed as well
    assert_equal(img2.coordmap.function_domain.coord_names,
                 img.coordmap.function_domain.coord_names[::-1])
    assert_equal(img2.coordmap.function_domain.coord_names,
                 ('i', 'j', 'k', 't'))

def test_write():
    fp, fname = mkstemp('.nii')
    img = load_image(funcfile)
    save_image(img, fname)
    test = FmriImageList.from_image(load_image(fname))
    yield assert_equal, test[0].affine.shape, (4,4)
    yield assert_equal, img[0].affine.shape, (5,4)

    # Check the affine...
    A = np.identity(4)
    A[:3,:3] = img[:,:,:,0].affine[:3,:3]
    A[:3,-1] = img[:,:,:,0].affine[:3,-1]
    yield assert_true, np.allclose(test[0].affine, A)

    # Under windows, if you don't close before delete, you get a
    # locking error.
    os.close(fp)
    os.remove(fname)