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Overview

The macros module provides lightweight helpers for the time conversions Basilisk relies on internally (all simulation times are integers in nanoseconds) and a set of common unit-conversion constants. 
from Basilisk.utilities import macros

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Time conversion functions

All conversion functions return an int (nanoseconds), suitable for direct use as task rates, stop times, and event rates.
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sec2nano(time)
function
Converts seconds to integer nanoseconds.
ns = macros.sec2nano(10.0)   # 10000000000
Returns int.
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min2nano(time)
function
Converts minutes to integer nanoseconds.
ns = macros.min2nano(90.0)   # 5400000000000
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hour2nano(time)
function
Converts hours to integer nanoseconds.
ns = macros.hour2nano(1.5)
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day2nano(time)
function
Converts days to integer nanoseconds.
ns = macros.day2nano(1.0)

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Time-unit constants

Use these to convert logged nanosecond timestamps back to human-readable units.
ConstantValueDescription
NANO2SEC1e-9Nanoseconds → seconds
NANO2MIN1/60 × 1e-9Nanoseconds → minutes
NANO2HOUR1/3600 × 1e-9Nanoseconds → hours
t_sec = dataLog.times() * macros.NANO2SEC

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Angular unit constants

ConstantValueDescription
D2Rπ / 180Degrees → radians
R2D180 / πRadians → degrees
RPM2π / 60RPM → rad/s
rpm2radsec2π / 60RPM → rad/s (alias)

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Usage example

from Basilisk.utilities import macros

# Task running at 10 Hz
taskRate = macros.sec2nano(0.1)          # [ns]

# Stop at 10 orbital periods (≈ 5700 s for LEO)
stopTime = macros.sec2nano(10 * 5700.0)  # [ns]

# Reaction wheel spin rate
omega_rw = 1500.0 * macros.RPM          # [rad/s]

# Convert result timestamps to seconds
t_s = dataLog.times() * macros.NANO2SEC  # [s]

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