umath: add stubs and docs for umath module

Issue: https://github.com/pybricks/support/issues/236

doc/api/index.rst

@@ -80,6 +80,7 @@ findings on our `support page`_ so we can make Pybricks even better.
    micropython
    uerrno
    uio
+   umath
    urandom
    uselect
    usys

doc/api/umath.rst

@@ -0,0 +1,4 @@
+:mod:`umath` -- Mathematical functions
+======================================
+
+.. automodule:: umath

pyproject.toml

@@ -18,6 +18,7 @@ packages = [
     { include = "micropython", from = "src" },
     { include = "uerrno", from = "src" },
     { include = "uio", from = "src" },
+    { include = "umath", from = "src" },
     { include = "urandom", from = "src" },
     { include = "uselect", from = "src" },
     { include = "usys", from = "src" },

src/umath/__init__.py

@@ -0,0 +1,190 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2021 The Pybricks Authors
+#
+# Portions of documentation copied from:
+# https://raw.githubusercontent.com/micropython/micropython/1e6d18c915ccea0b6a19ffec9710d33dd7e5f866/docs/library/math.rst
+# Copyright (c) 2014-2021, Damien P. George, Paul Sokolovsky, and contributors
+
+"""
+This module provides some basic mathematical functions for
+working with floating-point numbers.
+
+.. note:: This module is not available on the BOOST Move hub.
+"""
+
+# constants
+
+from typing import Tuple
+
+
+e: float
+"""
+Base of the natural logarithm.
+"""
+
+pi: float
+"""
+The ratio of a circle's circumference to its diameter.
+"""
+
+# functions
+
+
+def acos(x: float) -> float:
+    """
+    Returns the inverse cosine of ``x``.
+    """
+
+
+def asin(x: float) -> float:
+    """
+    Returns the inverse sine of ``x``.
+    """
+
+
+def atan(x: float) -> float:
+    """
+    Returns the inverse tangent of ``x``.
+    """
+
+
+def atan2(y: float, x: float) -> float:
+    """
+    Returns the principal value of the inverse tangent of ``y/x``.
+    """
+
+
+def ceil(x: float) -> int:
+    """
+    Returns an integer, being ``x`` rounded towards positive infinity.
+    """
+
+
+def copysign(x: float, y: float) -> float:
+    """
+    Returns ``x`` with the sign of ``y``.
+    """
+
+
+def cos(x: float) -> float:
+    """
+    Returns the cosine of ``x``.
+    """
+
+
+def degrees(x: float) -> float:
+    """
+    Returns radians ``x`` converted to degrees.
+    """
+
+
+def exp(x: float) -> float:
+    """
+    Returns the exponential of ``x``.
+    """
+
+
+def fabs(x: float) -> float:
+    """
+    Returns the absolute value of ``x``.
+
+    Use ``abs(x)`` instead for integers.
+    """
+
+
+def floor(x: float) -> float:
+    """
+    Returns an integer, being ``x`` rounded towards negative infinity.
+    """
+
+
+def fmod(x: float, y: float) -> float:
+    """
+    Returns the remainder of ``x/y``.
+
+    Use ``x % y`` instead for integers.
+    """
+
+
+def frexp(x: float) -> Tuple[float, int]:
+    """
+    Decomposes a floating-point number into its mantissa and exponent.
+    The returned value is the tuple ``(m, e)`` such that ``x == m * 2**e``
+    exactly.  If ``x == 0`` then the function returns ``(0.0, 0)``, otherwise
+    the relation ``0.5 <= abs(m) < 1`` holds.
+    """
+
+
+def isfinite(x: float) -> bool:
+    """
+    Returns ``True`` if ``x`` is finite.
+    """
+
+
+def isinf(x: float) -> bool:
+    """
+    Returns ``True`` if ``x`` is infinite.
+    """
+
+
+def isnan(x: float) -> bool:
+    """
+    Returns ``True`` if ``x`` is not-a-number
+    """
+
+
+def ldexp(x: float, exp: int) -> float:
+    """
+    Returns ``x * (2**exp)``.
+    """
+
+
+def log(x: float) -> float:
+    """
+    Returns the natural logarithm of ``x``.
+    """
+
+
+def modf(x: float) -> Tuple[float, float]:
+    """
+    Returns a tuple of two floats, being the fractional and integral parts of
+    ``x``.  Both return values have the same sign as ``x``.
+    """
+
+
+def pow(x: float, y: float) -> float:
+    """
+    Returns ``x`` to the power of ``y``.
+
+    Use ``x ** y`` instead for intergers.
+    """
+
+
+def radians(x: float) -> float:
+    """
+    Returns degrees ``x`` converted to radians.
+    """
+
+
+def sin(x: float) -> float:
+    """
+    Returns the sine of ``x``.
+    """
+
+
+def sqrt(x: float) -> float:
+    """
+    Returns the square root of ``x``.
+    """
+
+
+def tan(x: float) -> float:
+    """
+    Returns the tangent of ``x``.
+    """
+
+
+def trunc(x: float) -> int:
+    """
+    Returns an integer, being ``x`` rounded towards 0.
+    """