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

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


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


.. index:: B0Calc

B0Calc
------

`Link to code <file:///build/nipype-8w24iI/nipype-1.1.1/nipype/interfaces/fsl/possum.py#L93>`__

Wraps 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)
                flag: -i %s, position: 0

        [Optional]
        args: (a unicode string)
                Additional parameters to the command
                flag: %s
        chi_air: (a float, nipype default value: 4e-07)
                susceptibility of air
                flag: --chi0=%e
        compute_xyz: (a boolean, nipype default value: False)
                calculate and save all 3 field components (i.e. x,y,z)
                flag: --xyz
        delta: (a float, nipype default value: -9.45e-06)
                Delta value (chi_tissue - chi_air)
                flag: -d %e
        directconv: (a boolean, nipype default value: False)
                use direct (image space) convolution, not FFT
                flag: --directconv
        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
        extendboundary: (a float, nipype default value: 1.0)
                Relative proportion to extend voxels at boundary
                flag: --extendboundary=%0.2f
        out_file: (a file name)
                filename of B0 output volume
                flag: -o %s, position: 1
        output_type: (u'NIFTI_PAIR' or u'NIFTI_PAIR_GZ' or u'NIFTI_GZ' or
                 u'NIFTI')
                FSL output type
        x_b0: (a float, nipype default value: 0.0)
                Value for zeroth-order b0 field (x-component), in Tesla
                flag: --b0x=%0.2f
                mutually_exclusive: xyz_b0
        x_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order x-gradient field (per mm)
                flag: --gx=%0.4f
        xyz_b0: (a tuple of the form: (a float, a float, a float))
                Zeroth-order B0 field in Tesla
                flag: --b0x=%0.2f --b0y=%0.2f --b0=%0.2f
                mutually_exclusive: x_b0, y_b0, z_b0
        y_b0: (a float, nipype default value: 0.0)
                Value for zeroth-order b0 field (y-component), in Tesla
                flag: --b0y=%0.2f
                mutually_exclusive: xyz_b0
        y_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order y-gradient field (per mm)
                flag: --gy=%0.4f
        z_b0: (a float, nipype default value: 1.0)
                Value for zeroth-order b0 field (z-component), in Tesla
                flag: --b0=%0.2f
                mutually_exclusive: xyz_b0
        z_grad: (a float, nipype default value: 0.0)
                Value for zeroth-order z-gradient field (per mm)
                flag: --gz=%0.4f

Outputs::

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

References::
None
