1 files changed, 107 insertions, 0 deletions
diff --git a/python/splitCCDgaps.py b/python/splitCCDgaps.py
new file mode 100644
index 0000000..bc26c29
--- /dev/null
+++ b/python/splitCCDgaps.py
@@ -0,0 +1,107 @@
+# -*- coding: utf-8-
+#
+# Aaron LI
+# 2015/08/12
+#
+
+"""
+Split the long-strip-shaped CCD gaps regions into a series of little
+square regions, which are used as the input regions of 'roi' to
+determine the corresponding background regions, and finally providied
+to 'dmfilth' in order to fill in the CCD gaps.
+"""
+
+
+import re
+import math
+from io import TextIOWrapper
+
+
+class BoxRegion(object):
+    """
+    CIAO/DS9 "rotbox"/"box" region class.
+
+    rotbox/box format:
+        rotbox(xc, yc, width, height, rotation)
+        box(xc, yc, width, height, rotation)
+    Notes:
+        rotation: [0, 360) (degree)
+    """
+    def __init__(self, xc=None, yc=None,
+                 width=None, height=None, rotation=None):
+        self.regtype  = "rotbox"
+        self.xc       = xc
+        self.yc       = yc
+        self.width    = width
+        self.height   = height
+        self.rotation = rotation
+
+    def __str__(self):
+        return "%s(%s,%s,%s,%s,%s)" % (self.regtype, self.xc, self.yc,
+                self.width, self.height, self.rotation)
+
+    @classmethod
+    def parse(cls, regstr):
+        """
+        Parse region string.
+        """
+        regex_box = re.compile(r'^(box|rotbox)\(([0-9.]+),([0-9.]+),([0-9.]+),([0-9.]+),([0-9.]+)\)$', re.I)
+        m = regex_box.match(regstr)
+        if m:
+            regtype  = m.group(1)
+            xc       = float(m.group(2))
+            yc       = float(m.group(3))
+            width    = float(m.group(4))
+            height   = float(m.group(5))
+            rotation = float(m.group(6))
+            return cls(xc, yc, width, height, rotation)
+        else:
+            return None
+
+    def split(self, filename=None):
+        """
+        Split long-strip-shaped box region into a series square box regions.
+        """
+        angle = self.rotation * math.pi / 180.0
+        # to record the center coordinates of each split region
+        centers = []
+        if self.width > self.height:
+            # number of regions after split
+            nreg = math.ceil(self.width / self.height)
+            # width & height of the split region
+            width = self.width / nreg
+            height = self.height
+            # position of the left-most region
+            x_l = self.xc - 0.5*self.width * math.cos(angle)
+            y_l = self.yc - 0.5*self.width * math.sin(angle)
+            for i in range(nreg):
+                x = x_l + (0.5 + i) * width * math.cos(angle)
+                y = y_l + (0.5 + i) * width * math.sin(angle)
+                centers.append((x, y))
+        else:
+            # number of regions after split
+            nreg = math.ceil(self.height / self.width)
+            # width & height of the split region
+            width = self.width
+            height = self.height / nreg
+            # position of the left-most region
+            x_l = self.xc + 0.5*self.height * math.cos(angle + math.pi/2)
+            y_l = self.yc + 0.5*self.height * math.sin(angle + math.pi/2)
+            for i in range(nreg):
+                x = x_l - (0.5 + i) * height * math.cos(angle + math.pi/2)
+                y = y_l - (0.5 + i) * height * math.sin(angle + math.pi/2)
+                centers.append((x, y))
+        # create split regions
+        regions = []
+        for (x, y) in centers:
+            regions.append(self.__class__(x, y, width+2, height+2,
+                                          self.rotation))
+        # write split regions into file if specified
+        if isinstance(filename, str):
+            regout = open(filename, "w")
+            regout.write("\n".join(map(str, regions)))
+            regout.close()
+        else:
+            return regions
+
+