RotType

class lsst.ts.observatory.control.RotType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

Available types of rotation, i.e. the meaning of the rot_angle argument in slew operations.

Sky: Rotate with the sky. The rotator is positioned with respect to the

North axis so rot_angle=0. means y-axis is aligned with North. Angle grows clock-wise.

SkyAuto: Same as sky position angle but it will verify that the requested

angle is achievable and wrap it to a valid range.

ParallacticSky: This strategy is required for taking optimum spectra with

LATISS. If set to zero, the rotator is positioned so that the y-axis (dispersion axis) is aligned with the parallactic angle. IMPORTANT: The position is set at the start of the slew operation and the rotator will then track the sky.

PhysicalSky: This strategy allows users to select the initial position

of the rotator in terms of the physical rotator angle (in the reference frame of the telescope). Note that the telescope will resume tracking the sky rotation.

Physical: Select a fixed position for the rotator in the reference frame of

the telescope. Rotator will not track in this mode.

Attributes Summary

Parallactic

Physical

PhysicalSky

Sky

SkyAuto

denominator

the denominator of a rational number in lowest terms

imag

the imaginary part of a complex number

numerator

the numerator of a rational number in lowest terms

real

the real part of a complex number

Methods Summary

as_integer_ratio(/)

Return integer ratio.

bit_count(/)

Number of ones in the binary representation of the absolute value of self.

bit_length(/)

Number of bits necessary to represent self in binary.

conjugate

Returns self, the complex conjugate of any int.

from_bytes(/, bytes[, byteorder, signed])

Return the integer represented by the given array of bytes.

to_bytes(/[, length, byteorder, signed])

Return an array of bytes representing an integer.

Attributes Documentation

Parallactic = 2
Physical = 4
PhysicalSky = 3
Sky = 0
SkyAuto = 1
denominator

the denominator of a rational number in lowest terms

imag

the imaginary part of a complex number

numerator

the numerator of a rational number in lowest terms

real

the real part of a complex number

Methods Documentation

as_integer_ratio(/)

Return integer ratio.

Return a pair of integers, whose ratio is exactly equal to the original int and with a positive denominator.

>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)
bit_count(/)

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

>>> bin(13)
'0b1101'
>>> (13).bit_count()
3
bit_length(/)

Number of bits necessary to represent self in binary.

>>> bin(37)
'0b100101'
>>> (37).bit_length()
6
conjugate()

Returns self, the complex conjugate of any int.

from_bytes(/, bytes, byteorder='big', *, signed=False)

Return the integer represented by the given array of bytes.

bytes

Holds the array of bytes to convert. The argument must either support the buffer protocol or be an iterable object producing bytes. Bytes and bytearray are examples of built-in objects that support the buffer protocol.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Indicates whether two’s complement is used to represent the integer.

to_bytes(/, length=1, byteorder='big', *, signed=False)

Return an array of bytes representing an integer.

length

Length of bytes object to use. An OverflowError is raised if the integer is not representable with the given number of bytes. Default is length 1.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Determines whether two’s complement is used to represent the integer. If signed is False and a negative integer is given, an OverflowError is raised.