def min_diff(x_ref, y_ref, x_vec, y_vec):
"""
functions to compute the mininum distance between a point and a array
Input
- x_ref float :
- y_ref float :
- x_vec float :
- y_vec float :
Output
-
#FIXME - finish documentation
"""
diff_pos = []
for i in range(len(x_vec)):
ra_diff = (x_ref - x_vec[i]) * math.cos(y_ref - y_vec[i])
dist = fc.modulus(ra_diff, (y_ref - y_vec[i]))
diff_pos.append(math.fabs(dist))
# print "----------"
# print min(diff_pos) * 60.0, "arcmin"
min_index = diff_pos.index(min(diff_pos))
# print x_ref, y_ref
# print x_vec[min_index], y_vec[min_index]
# print "----------"
#print min(diff_pos)*60.0, min_index
return min(diff_pos) * 60.0, min_index
def max_diff(ra_ref, dec_ref, ra_vec, dec_vec):
"""
Function to compute the maximun distance between a point and a set of points
Input
- ra_ref float :
- def_ref float :
- ra_vec float :
- dec_vec float :
Output
-
#FIXME - finish documentation
"""
if (type(ra_vec) != np.array):
ra_vec = np.array(ra_vec)
if (type(dec_vec) != np.array):
dec_vec = np.array(dec_vec)
diff_pos = []
for i in range(len(ra_vec)):
ra_diff = (ra_ref - ra_vec[i]) * math.cos(dec_ref - dec_vec[i])
dist = fc.modulus( ra_diff, (dec_ref - dec_vec[i]) )
diff_pos.append( math.fabs(dist) )
max_index = diff_pos.index( max(diff_pos) )
max_index1 = np.where( ra_vec == ra_vec[max_index] )
return max(diff_pos)*60.0, max_index1[0][0]
def min_diff_mask(x_ref, y_ref, x_vec, y_vec, tolerance=1.5):
"""
Optimized functions to compute the mininum distance between a point and a array
Input
- x_ref float :
- y_ref float :
- x_vec float :
- y_vec float :
- toll float :
Output
-
#FIXME - finish documentation
"""
x_min = x_ref - tolerance
x_max = x_ref + tolerance
y_min = y_ref - tolerance
y_max = y_ref + tolerance
if (type(x_vec) != np.array):
x_vec = np.array(x_vec)
if (type(y_vec) != np.array):
y_vec = np.array(y_vec)
msk = (x_vec >= x_min) & (x_vec <= x_max) & \
(y_vec >= y_min) & (y_vec <= y_max)
x_vec_msk = x_vec[msk]
y_vec_msk = y_vec[msk]
#print len(x_vec_msk), len(y_vec_msk)
if len(x_vec_msk) == 0:
return 1000, -1
diff_pos = []
for i in range(len(x_vec_msk)):
ra_diff = (x_ref - x_vec_msk[i]) * math.cos(y_ref - y_vec_msk[i])
dist = fc.modulus(ra_diff, (y_ref - y_vec_msk[i]))
diff_pos.append(math.fabs(dist))
min_index = diff_pos.index(min(diff_pos))
min_index1 = np.where(x_vec == x_vec_msk[min_index])
#min_index2 = np.where( y_vec == y_vec_msk[min_index] )
#print min_index1[0][0], min_index2[0][0]
#print min(diff_pos)*60.0, min_index1[0][0]
return min(diff_pos) * 60.0, min_index1[0][0]