.. AUTO-GENERATED FILE -- DO NOT EDIT!

interfaces.fsl.possum
=====================


.. _nipype.interfaces.fsl.possum.B0Calc:


.. index:: B0Calc

B0Calc
------

`Link to code <file:///build/nipype-1.1.8/nipype/interfaces/fsl/possum.py#L93>`__

Wraps the executable command ``b0calc``.

B0 inhomogeneities occur at interfaces of materials with different magnetic susceptibilities,
such as tissue-air interfaces. These differences lead to distortion in the local magnetic field,
as Maxwell’s equations need to be satisfied. An example of B0 inhomogneity is the first volume
of the 4D volume ```$FSLDIR/data/possum/b0_ppm.nii.gz```.

Examples
~~~~~~~~

>>> from nipype.interfaces.fsl import B0Calc
>>> b0calc = B0Calc()
>>> b0calc.inputs.in_file = 'tissue+air_map.nii'
>>> b0calc.inputs.z_b0 = 3.0
>>> b0calc.inputs.output_type = "NIFTI_GZ"
>>> b0calc.cmdline
'b0calc -i tissue+air_map.nii -o tissue+air_map_b0field.nii.gz --chi0=4.000000e-07 -d -9.450000e-06 --extendboundary=1.00 --b0x=0.00 --gx=0.0000 --b0y=0.00 --gy=0.0000 --b0=3.00 --gz=0.0000'

Inputs::

        [Mandatory]
        in_file: (an existing file name)
                filename of input image (usually a tissue/air segmentation)
                argument: ``-i %s``, position: 0

        [Optional]
        x_b0: (a float, nipype default value: 0.0)
                Value for zeroth-order b0 field (x-component), in Tesla
                argument: ``--b0x=%0.2f``
                mutually_exclusive: xyz_b0
        directconv: (a boolean, nipype default value: False)
                use direct (image space) convolution, not FFT
                argument: ``--directconv``
        out_file: (a file name)
                filename of B0 output volume
                argument: ``-o %s``, position: 1
        z_b0: (a float, nipype default value: 1.0)
                Value for zeroth-order b0 field (z-component), in Tesla
                argument: ``--b0=%0.2f``
                mutually_exclusive: xyz_b0
        xyz_b0: (a tuple of the form: (a float, a float, a float))
                Zeroth-order B0 field in Tesla
                argument: ``--b0x=%0.2f --b0y=%0.2f --b0=%0.2f``
                mutually_exclusive: x_b0, y_b0, z_b0
        args: (a unicode string)
                Additional parameters to the command
                argument: ``%s``
        compute_xyz: (a boolean, nipype default value: False)
                calculate and save all 3 field components (i.e. x,y,z)
                argument: ``--xyz``
        y_b0: (a float, nipype default value: 0.0)
                Value for zeroth-order b0 field (y-component), in Tesla
                argument: ``--b0y=%0.2f``
                mutually_exclusive: xyz_b0
        z_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order z-gradient field (per mm)
                argument: ``--gz=%0.4f``
        environ: (a dictionary with keys which are a newbytes or None or a
                  newstr or None and with values which are a newbytes or None or a
                  newstr or None, nipype default value: {})
                Environment variables
        x_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order x-gradient field (per mm)
                argument: ``--gx=%0.4f``
        delta: (a float, nipype default value: -9.45e-06)
                Delta value (chi_tissue - chi_air)
                argument: ``-d %e``
        chi_air: (a float, nipype default value: 4e-07)
                susceptibility of air
                argument: ``--chi0=%e``
        output_type: (u'NIFTI_PAIR' or u'NIFTI_PAIR_GZ' or u'NIFTI_GZ' or
                  u'NIFTI')
                FSL output type
        y_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order y-gradient field (per mm)
                argument: ``--gy=%0.4f``
        extendboundary: (a float, nipype default value: 1.0)
                Relative proportion to extend voxels at boundary
                argument: ``--extendboundary=%0.2f``

Outputs::

        out_file: (an existing file name)
                filename of B0 output volume

References:
~~~~~~~~~~~
None
