LSST Applications  21.0.0-172-gfb10e10a+18fedfabac,22.0.0+297cba6710,22.0.0+80564b0ff1,22.0.0+8d77f4f51a,22.0.0+a28f4c53b1,22.0.0+dcf3732eb2,22.0.1-1-g7d6de66+2a20fdde0d,22.0.1-1-g8e32f31+297cba6710,22.0.1-1-geca5380+7fa3b7d9b6,22.0.1-12-g44dc1dc+2a20fdde0d,22.0.1-15-g6a90155+515f58c32b,22.0.1-16-g9282f48+790f5f2caa,22.0.1-2-g92698f7+dcf3732eb2,22.0.1-2-ga9b0f51+7fa3b7d9b6,22.0.1-2-gd1925c9+bf4f0e694f,22.0.1-24-g1ad7a390+a9625a72a8,22.0.1-25-g5bf6245+3ad8ecd50b,22.0.1-25-gb120d7b+8b5510f75f,22.0.1-27-g97737f7+2a20fdde0d,22.0.1-32-gf62ce7b1+aa4237961e,22.0.1-4-g0b3f228+2a20fdde0d,22.0.1-4-g243d05b+871c1b8305,22.0.1-4-g3a563be+32dcf1063f,22.0.1-4-g44f2e3d+9e4ab0f4fa,22.0.1-42-gca6935d93+ba5e5ca3eb,22.0.1-5-g15c806e+85460ae5f3,22.0.1-5-g58711c4+611d128589,22.0.1-5-g75bb458+99c117b92f,22.0.1-6-g1c63a23+7fa3b7d9b6,22.0.1-6-g50866e6+84ff5a128b,22.0.1-6-g8d3140d+720564cf76,22.0.1-6-gd805d02+cc5644f571,22.0.1-8-ge5750ce+85460ae5f3,master-g6e05de7fdc+babf819c66,master-g99da0e417a+8d77f4f51a,w.2021.48
LSST Data Management Base Package
_rotateBBoxBy90.py
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1 # This file is part of afw.
2 #
3 # Developed for the LSST Data Management System.
4 # This product includes software developed by the LSST Project
5 # (https://www.lsst.org).
6 # See the COPYRIGHT file at the top-level directory of this distribution
7 # for details of code ownership.
8 #
9 # This program is free software: you can redistribute it and/or modify
10 # it under the terms of the GNU General Public License as published by
11 # the Free Software Foundation, either version 3 of the License, or
12 # (at your option) any later version.
13 #
14 # This program is distributed in the hope that it will be useful,
15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 # GNU General Public License for more details.
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20 # along with this program. If not, see <https://www.gnu.org/licenses/>.
21 
22 __all__ = ["rotateBBoxBy90"]
23 
24 import numpy
25 
26 import lsst.geom
27 
28 
29 def rotateBBoxBy90(bbox, n90, dimensions):
30  """Rotate a bounding box by an integer multiple of 90 degrees.
31 
32  Parameters
33  ----------
34  bbox : `lsst.geom.Box2I`
35  Bounding box to rotate.
36  n90 : `int`
37  Number of quarter rotations to perform
38  dimensions : `tuple` of `int`
39  Dimensions of the parent grid.
40 
41  Returns
42  -------
43  newBbox : `lsst.geom.Box`
44  Rotated bounding box.
45 
46  Notes
47  -----
48  **TODO:**
49  document dimensions better; what does it specify?
50  """
51  while n90 < 0:
52  n90 += 4
53  n90 %= 4
54 
55  # sin/cos of the rotation angle
56  s = 0
57  c = 0
58  if n90 == 0:
59  s = 0
60  c = 1
61  elif n90 == 1:
62  s = 1
63  c = 0
64  elif n90 == 2:
65  s = 0
66  c = -1
67  elif n90 == 3:
68  s = -1
69  c = 0
70  else:
71  raise ValueError("n90 must be an integer")
72 
73  centerPixel = lsst.geom.Point2I(int(dimensions[0]/2), int(dimensions[1]/2))
74 
75  xCorner = numpy.array([(corner.getX() - centerPixel[0])
76  for corner in bbox.getCorners()])
77  yCorner = numpy.array([(corner.getY() - centerPixel[1])
78  for corner in bbox.getCorners()])
79  x0 = int((c*xCorner - s*yCorner).min())
80  y0 = int((s*xCorner + c*yCorner).min())
81  x1 = int((c*xCorner - s*yCorner).max())
82  y1 = int((s*xCorner + c*yCorner).max())
83 
84  # Fiddle things a little if the detector has an even number of pixels so that square BBoxes
85  # will map into themselves
86 
87  if n90 == 1:
88  if dimensions[0]%2 == 0:
89  x0 -= 1
90  x1 -= 1
91  elif n90 == 2:
92  if dimensions[0]%2 == 0:
93  x0 -= 1
94  x1 -= 1
95  if dimensions[1]%2 == 0:
96  y0 -= 1
97  y1 -= 1
98  elif n90 == 3:
99  if dimensions[1]%2 == 0:
100  y0 -= 1
101  y1 -= 1
102 
103  LLC = lsst.geom.Point2I(centerPixel[0] + x0, centerPixel[1] + y0)
104  URC = lsst.geom.Point2I(centerPixel[0] + x1, centerPixel[1] + y1)
105 
106  newBbox = lsst.geom.Box2I(LLC, URC)
107 
108  dxy0 = centerPixel[0] - centerPixel[1]
109  if n90%2 == 1 and not dxy0 == 0:
110  newBbox.shift(lsst.geom.Extent2I(-dxy0, dxy0))
111 
112  return newBbox
int min
int max
An integer coordinate rectangle.
Definition: Box.h:55
def rotateBBoxBy90(bbox, n90, dimensions)