Radesys

plotastrodata/fits_utils.py

@@ -130,7 +130,11 @@ def get_center(self) -> str:
         """
         ra_deg = self.get_header('CRVAL1')
         dec_deg = self.get_header('CRVAL2')
-        return xy2coord([ra_deg, dec_deg])
+        radesys = self.get_header('RADESYS')
+        a = xy2coord([ra_deg, dec_deg])
+        if radesys is not None:
+            a = f'{radesys} {a}'
+        return a
 
     def gen_data(self, Tb: bool = False, log: bool = False,
                  drop: bool = True, restfreq: float = None) -> None:
@@ -180,6 +184,9 @@ def gen_grid(self, center: str | None = None, dist: float = 1.,
         # spatial center
         if center is not None:
             c0 = xy2coord([h['CRVAL1'], h['CRVAL2']])
+            if 'RADESYS' in h:
+                radesys = h['RADESYS']
+                c0 = f'{radesys}  {c0}'
             cx, cy = coord2xy(center, c0)
         else:
             cx, cy = 0, 0

plotastrodata/other_utils.py

@@ -1,7 +1,7 @@
 import subprocess
 import shlex
 import numpy as np
-from astropy.coordinates import SkyCoord
+from astropy.coordinates import SkyCoord, FK5, FK4
 from astropy import units
 from scipy.optimize import curve_fit
 from scipy.special import erf
@@ -42,38 +42,117 @@ def listing(*args) -> list:
     return b
 
 
-def coord2xy(coords: str, coordorg: str = '00h00m00s 00d00m00s',
-             frame: str = 'icrs', frameorg: str = 'icrs') -> np.ndarray:
+def _getframe(coord: str, s: str = '') -> tuple:
+    """Internal function to pick up the frame name from the coordinates.
+
+    Args:
+        coord (str): something like "J2000 01h23m45.6s 01d23m45.6s"
+        s (str, optional): To distinguish coord and coordorg. Defaults to ''.
+
+    Returns:
+        tuple: updated coord and frame. frame is FK5(equinox='J2000), FK4(equinox='B1950'), or 'icrs'.
+    """
+    if len(c := coord.split()) == 3:
+        coord = f'{c[1]} {c[2]}'
+        if 'J2000' in c[0]:
+            print(f'J2000 found in coord{s}. FK5(J2000) is used.')
+            frame = FK5(equinox='J2000')
+        elif 'FK5' in c[0]:
+            print(f'FK5 found in coord{s}. FK5(J2000) is used.')
+            frame = FK5(equinox='J2000')
+        elif 'B1950' in c[0]:
+            print(f'B1950 found in coord{s}. FK4(B1950) is used.')
+            frame = FK4(equinox='B1950')
+        elif 'FK4' in c[0]:
+            print(f'FK4 found in coord{s}. FK4(B1950) is used.')
+            frame = FK4(equinox='B1950')
+        elif 'ICRS' in c[0]:
+            frame = 'icrs'
+        else:
+            print(f'Unknown equinox found in coord{s}. ICRS is used')
+            frame = 'icrs'
+    else:
+        frame = None
+    return coord, frame
+
+
+def _updateframe(frame: str) -> str:
+    """Internal function to str frame to astropy frame.
+
+    Args:
+        frame (str): _description_
+
+    Returns:
+        str: frame as is, FK5(equinox='J2000'), FK4(equinox='B1950'), or 'icrs'.
+    """
+    if 'ICRS' in frame:
+        a = 'icrs'
+    elif 'J2000' in frame or 'FK5' in frame:
+        a = FK5(equinox='J2000')
+    elif 'B1950' in frame or 'FK4' in frame:
+        a = FK4(equinox='B1950')
+    else:
+        a = frame
+    return a
+
+
+def coord2xy(coords: str | list, coordorg: str = '00h00m00s 00d00m00s',
+             frame: str | None = None, frameorg: str | None = None,
+             ) -> np.ndarray:
     """Transform R.A.-Dec. to relative (deg, deg).
 
     Args:
-        coords (str): something like '01h23m45.6s 01d23m45.6s'. The input can be a list of str in an arbitrary shape.
-        coordorg (str): something like '01h23m45.6s 01d23m45.6s'. The origin of the relative (deg, deg). Defaults to '00h00m00s 00d00m00s'.
-        frame (str): coordinate frame. Defaults to 'icrs'.
-        frameorg (str): coordinate frame of the origin. Defaults to 'icrs'.
+        coords (str, list): something like '01h23m45.6s 01d23m45.6s'. The input can be a list of str in an arbitrary shape.
+        coordorg (str, optional): something like '01h23m45.6s 01d23m45.6s'. The origin of the relative (deg, deg). Defaults to '00h00m00s 00d00m00s'.
+        frame (str, optional): coordinate frame. Defaults to None.
+        frameorg (str, optional): coordinate frame of the origin. Defaults to None.
 
     Returns:
         np.ndarray: [(array of) alphas, (array of) deltas] in degree. The shape of alphas and deltas is the input shape. With a single input, the output is [alpha0, delta0].
     """
+    coordorg, frameorg_c = _getframe(coordorg, 'org')
+    frameorg = frameorg_c if frameorg is None else _updateframe(frameorg)
+    if type(coords) is list:
+        for i in range(len(coords)):
+            coords[i], frame_c = _getframe(coords[i])
+    else:
+        coords, frame_c = _getframe(coords)
+    frame = frame_c if frame is None else _updateframe(frame)
+    if frame is None and frameorg is not None:
+        frame = frameorg
+    if frame is not None and frameorg is None:
+        frameorg = frame
+    if frame is None and frameorg is None:
+        frame = frameorg = 'icrs'
+    if frame != frameorg:
+        frame = frameorg
+        print('Different frame and frameorg are not supported by coord2xy yet.',
+              frameorg, 'is used.')
     clist = SkyCoord(coords, frame=frame)
     c0 = SkyCoord(coordorg, frame=frameorg)
     xy = c0.spherical_offsets_to(clist)
     return np.array([xy[0].degree, xy[1].degree])
 
 
 def xy2coord(xy: list, coordorg: str = '00h00m00s 00d00m00s',
-             frame: str = 'icrs', frameorg: str = 'icrs') -> str:
+             frame: str | None = None, frameorg: str | None = None,
+             ) -> str:
     """Transform relative (deg, deg) to R.A.-Dec.
 
     Args:
         xy (list): [(array of) alphas, (array of) deltas] in degree. alphas and deltas can have an arbitrary shape.
         coordorg (str): something like '01h23m45.6s 01d23m45.6s'. The origin of the relative (deg, deg). Defaults to '00h00m00s 00d00m00s'.
-        frame (str): coordinate frame. Defaults to 'icrs'.
-        frameorg (str): coordinate frame of the origin. Defaults to 'icrs'.
+        frame (str): coordinate frame. Defaults to None.
+        frameorg (str): coordinate frame of the origin. Defaults to None.
 
     Returns:
         str: something like '01h23m45.6s 01d23m45.6s'. With multiple inputs, the output has the input shape.
     """
+    coordorg, frameorg_c = _getframe(coordorg, 'org')
+    frameorg = frameorg_c if frameorg is None else _updateframe(frameorg)
+    if frameorg is None:
+        frameorg = 'icrs'
+    frame = frameorg if frame is None else _updateframe(frame)
     c0 = SkyCoord(coordorg, frame=frameorg)
     coords = c0.spherical_offsets_by(*xy * units.degree)
     coords = coords.transform_to(frame=frame)

plotastrodata/plot_utils.py

@@ -935,6 +935,9 @@ def set_axis_radec(self, center: str | None = None,
             center = self.center
         if center is None:
             center = '00h00m00s 00d00m00s'
+        if len(csplit := center.split()) == 3:
+            center = f'{csplit[1]} {csplit[2]}'
+        print(center)
         dec = np.radians(coord2xy(center)[1])
 
         def get_sec(x, i):