From 82c96206faa9f1defcdd6dd5f254899b5e98b644 Mon Sep 17 00:00:00 2001
From: Paul McCarthy <pauldmccarthy@gmail.com>
Date: Sun, 23 Jul 2017 11:35:23 +0100
Subject: [PATCH] transform method now has a 'vector' option, which skips
translation.
---
fsl/utils/transform.py | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/fsl/utils/transform.py b/fsl/utils/transform.py
index 4c5c21bdb..79ab8c414 100644
--- a/fsl/utils/transform.py
+++ b/fsl/utils/transform.py
@@ -412,24 +412,28 @@ def axisBounds(shape,
else: return (lo, hi)
-def transform(p, xform, axes=None):
+def transform(p, xform, axes=None, vector=False):
"""Transforms the given set of points ``p`` according to the given affine
transformation ``xform``.
- :arg p: A sequence or array of points of shape :math:`N \\times 3`.
+ :arg p: A sequence or array of points of shape :math:`N \\times 3`.
- :arg xform: An affine transformation matrix with which to transform the
- points in ``p``.
+ :arg xform: An affine transformation matrix with which to transform the
+ points in ``p``.
- :arg axes: If you are only interested in one or two axes, and the source
- axes are orthogonal to the target axes (see the note below),
- you may pass in a 1D, ``N*1``, or ``N*2`` array as ``p``, and
- use this argument to specify which axis/axes that the data in
- ``p`` correspond to.
+ :arg axes: If you are only interested in one or two axes, and the source
+ axes are orthogonal to the target axes (see the note below),
+ you may pass in a 1D, ``N*1``, or ``N*2`` array as ``p``, and
+ use this argument to specify which axis/axes that the data in
+ ``p`` correspond to.
- :returns: The points in ``p``, transformed by ``xform``, as a ``numpy``
- array with the same data type as the input.
+ :arg vector: Defaults to ``False``. If ``True``, the points are treated
+ as vectors - the translation component of the transformation
+ is not applied.
+
+ :returns: The points in ``p``, transformed by ``xform``, as a ``numpy``
+ array with the same data type as the input.
.. note:: The ``axes`` argument should only be used if the source
@@ -442,7 +446,10 @@ def transform(p, xform, axes=None):
"""
p = _fillPoints(p, axes)
- t = np.dot(xform[:3, :3], p.T).T + xform[:3, 3]
+ t = np.dot(xform[:3, :3], p.T).T
+
+ if not vector:
+ t = t + xform[:3, 3]
if axes is not None:
t = t[:, axes]
--
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