Merge branch 'master' into comparisons

18 files changed, 480 insertions, 215 deletions

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..8383fff
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+CHANGES merge=union
diff --git a/.gitignore b/.gitignore
index ce943ca..2d9bf37 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,7 @@ notebooks/pandas_test.csv
 
 # dask stuff
 dask-worker-space
+
+# airspeed velocity bechmark
+.asv/
+benchmarks/hashes.txt
diff --git a/.travis.yml b/.travis.yml
index 9c1a669..e180fd3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@ env:
 
   - PKGS="python=3.7 flake8 black==19.10b0 isort"  # Have linters fail first and quickly
   # Pinned packages to match readthedocs CI https://readthedocs.org/projects/pint/
-  - PKGS="python=3.7 ipython matplotlib nbsphinx numpy pandas jupyter_client ipykernel python-graphviz graphviz xarray sparse dask[complete] sphinx Pygments==2.3.1 docutils==0.14 alabaster commonmark==0.8.1 recommonmark==0.5.0"
+  - PKGS="python=3.7 ipython matplotlib nbsphinx numpy pandas==1.1.3 jupyter_client ipykernel python-graphviz graphviz xarray sparse dask[complete] sphinx Pygments==2.3.1 docutils==0.14 alabaster commonmark==0.8.1 recommonmark==0.5.0 babel==2.8"
   - PKGS="python=3.6"
   - PKGS="python=3.7"
   - PKGS="python=3.8"
diff --git a/CHANGES b/CHANGES
index 83498df..066a285 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,7 @@ Pint Changelog
 
 - Fix comparisons between Quantities and Measurements.
    (Issue #1134)
+- Implemented benchmarks based on airspeed velocity.
 
 
 0.16.1 (2020-09-22)
diff --git a/asv.conf.json b/asv.conf.json
new file mode 100644
index 0000000..dcc4857
--- /dev/null
+++ b/asv.conf.json
@@ -0,0 +1,160 @@
+{
+    // The version of the config file format.  Do not change, unless
+    // you know what you are doing.
+    "version": 1,
+
+    // The name of the project being benchmarked
+    "project": "pint",
+
+    // The project's homepage
+    "project_url": "https://github.com/hgrecco/pint",
+
+    // The URL or local path of the source code repository for the
+    // project being benchmarked
+    "repo": ".",
+
+    // The Python project's subdirectory in your repo.  If missing or
+    // the empty string, the project is assumed to be located at the root
+    // of the repository.
+    // "repo_subdir": "",
+
+    // Customizable commands for building, installing, and
+    // uninstalling the project. See asv.conf.json documentation.
+    //
+    // "install_command": ["in-dir={env_dir} python -mpip install {wheel_file}"],
+    // "uninstall_command": ["return-code=any python -mpip uninstall -y {project}"],
+    // "build_command": [
+    //     "python setup.py build",
+    //     "PIP_NO_BUILD_ISOLATION=false python -mpip wheel --no-deps --no-index -w {build_cache_dir} {build_dir}"
+    // ],
+
+    // List of branches to benchmark. If not provided, defaults to "master"
+    // (for git) or "default" (for mercurial).
+    // "branches": ["master"], // for git
+    // "branches": ["default"],    // for mercurial
+
+    // The DVCS being used.  If not set, it will be automatically
+    // determined from "repo" by looking at the protocol in the URL
+    // (if remote), or by looking for special directories, such as
+    // ".git" (if local).
+    // "dvcs": "git",
+
+    // The tool to use to create environments.  May be "conda",
+    // "virtualenv" or other value depending on the plugins in use.
+    // If missing or the empty string, the tool will be automatically
+    // determined by looking for tools on the PATH environment
+    // variable.
+    "environment_type": "conda",
+
+    // timeout in seconds for installing any dependencies in environment
+    // defaults to 10 min
+    //"install_timeout": 600,
+
+    // the base URL to show a commit for the project.
+    "show_commit_url": "http://github.com/hgrecco/pint/commit/",
+
+    // The Pythons you'd like to test against.  If not provided, defaults
+    // to the current version of Python used to run `asv`.
+    "pythons": ["3.9"],
+
+    // The list of conda channel names to be searched for benchmark
+    // dependency packages in the specified order
+    // "conda_channels": ["conda-forge", "defaults"],
+
+    // The matrix of dependencies to test.  Each key is the name of a
+    // package (in PyPI) and the values are version numbers.  An empty
+    // list or empty string indicates to just test against the default
+    // (latest) version. null indicates that the package is to not be
+    // installed. If the package to be tested is only available from
+    // PyPi, and the 'environment_type' is conda, then you can preface
+    // the package name by 'pip+', and the package will be installed via
+    // pip (with all the conda available packages installed first,
+    // followed by the pip installed packages).
+
+    "matrix": {
+         "numpy": ["1.19"],
+    //     "six": ["", null],        // test with and without six installed
+    //     "pip+emcee": [""],   // emcee is only available for install with pip.
+    },
+
+    // Combinations of libraries/python versions can be excluded/included
+    // from the set to test. Each entry is a dictionary containing additional
+    // key-value pairs to include/exclude.
+    //
+    // An exclude entry excludes entries where all values match. The
+    // values are regexps that should match the whole string.
+    //
+    // An include entry adds an environment. Only the packages listed
+    // are installed. The 'python' key is required. The exclude rules
+    // do not apply to includes.
+    //
+    // In addition to package names, the following keys are available:
+    //
+    // - python
+    //     Python version, as in the *pythons* variable above.
+    // - environment_type
+    //     Environment type, as above.
+    // - sys_platform
+    //     Platform, as in sys.platform. Possible values for the common
+    //     cases: 'linux2', 'win32', 'cygwin', 'darwin'.
+    //
+    // "exclude": [
+    //     {"python": "3.2", "sys_platform": "win32"}, // skip py3.2 on windows
+    //     {"environment_type": "conda", "six": null}, // don't run without six on conda
+    // ],
+    //
+    // "include": [
+    //     // additional env for python2.7
+    //     {"python": "2.7", "numpy": "1.8"},
+    //     // additional env if run on windows+conda
+    //     {"platform": "win32", "environment_type": "conda", "python": "2.7", "libpython": ""},
+    // ],
+
+    // The directory (relative to the current directory) that benchmarks are
+    // stored in.  If not provided, defaults to "benchmarks"
+    // "benchmark_dir": "benchmarks",
+
+    // The directory (relative to the current directory) to cache the Python
+    // environments in.  If not provided, defaults to "env"
+    "env_dir": ".asv/env",
+
+    // The directory (relative to the current directory) that raw benchmark
+    // results are stored in.  If not provided, defaults to "results".
+    "results_dir": ".asv/results",
+
+    // The directory (relative to the current directory) that the html tree
+    // should be written to.  If not provided, defaults to "html".
+    "html_dir": ".asv/html",
+
+    // The number of characters to retain in the commit hashes.
+    // "hash_length": 8,
+
+    // `asv` will cache results of the recent builds in each
+    // environment, making them faster to install next time.  This is
+    // the number of builds to keep, per environment.
+    // "build_cache_size": 2,
+
+    // The commits after which the regression search in `asv publish`
+    // should start looking for regressions. Dictionary whose keys are
+    // regexps matching to benchmark names, and values corresponding to
+    // the commit (exclusive) after which to start looking for
+    // regressions.  The default is to start from the first commit
+    // with results. If the commit is `null`, regression detection is
+    // skipped for the matching benchmark.
+    //
+    // "regressions_first_commits": {
+    //    "some_benchmark": "352cdf",  // Consider regressions only after this commit
+    //    "another_benchmark": null,   // Skip regression detection altogether
+    // },
+
+    // The thresholds for relative change in results, after which `asv
+    // publish` starts reporting regressions. Dictionary of the same
+    // form as in ``regressions_first_commits``, with values
+    // indicating the thresholds.  If multiple entries match, the
+    // maximum is taken. If no entry matches, the default is 5%.
+    //
+    // "regressions_thresholds": {
+    //    "some_benchmark": 0.01,     // Threshold of 1%
+    //    "another_benchmark": 0.5,   // Threshold of 50%
+    // },
+}
diff --git a/bench/bench.py b/bench/bench.py
deleted file mode 100644
index c3c9323..0000000
--- a/bench/bench.py
+++ /dev/null
@@ -1,146 +0,0 @@
-import copy
-import fnmatch
-import os
-from timeit import Timer
-
-import yaml
-
-
-def time_stmt(stmt="pass", setup="pass", number=0, repeat=3):
-    """Timer function with the same behaviour as running `python -m timeit `
-    in the command line.
-
-    Parameters
-    ----------
-    stmt : str
-         (Default value = "pass")
-    setup : str
-         (Default value = "pass")
-    number : int
-         (Default value = 0)
-    repeat : int
-         (Default value = 3)
-
-    Returns
-    -------
-    float
-        elapsed time in seconds or NaN if the command failed.
-
-    """
-
-    t = Timer(stmt, setup)
-
-    if not number:
-        # determine number so that 0.2 <= total time < 2.0
-        for i in range(1, 10):
-            number = 10 ** i
-
-            try:
-                x = t.timeit(number)
-            except Exception:
-                print(t.print_exc())
-                return float("NaN")
-
-            if x >= 0.2:
-                break
-
-    try:
-        r = t.repeat(repeat, number)
-    except Exception:
-        print(t.print_exc())
-        return float("NaN")
-
-    best = min(r)
-
-    return best / number
-
-
-def build_task(task, name="", setup="", number=0, repeat=3):
-    nt = copy.copy(task)
-
-    nt["name"] = (name + " " + task.get("name", "")).strip()
-    nt["setup"] = (setup + "\n" + task.get("setup", "")).strip("\n")
-    nt["stmt"] = task.get("stmt", "")
-    nt["number"] = task.get("number", number)
-    nt["repeat"] = task.get("repeat", repeat)
-
-    return nt
-
-
-def time_task(name, stmt="pass", setup="pass", number=0, repeat=3, stmts="", base=""):
-
-    if base:
-        nvalue = time_stmt(stmt=base, setup=setup, number=number, repeat=repeat)
-        yield name + " (base)", nvalue
-        suffix = " (normalized)"
-    else:
-        nvalue = 1.0
-        suffix = ""
-
-    if stmt:
-        value = time_stmt(stmt=stmt, setup=setup, number=number, repeat=repeat)
-        yield name, value / nvalue
-
-    for task in stmts:
-        new_task = build_task(task, name, setup, number, repeat)
-        for task_name, value in time_task(**new_task):
-            yield task_name + suffix, value / nvalue
-
-
-def time_file(filename, name="", setup="", number=0, repeat=3):
-    """Open a yaml benchmark file an time each statement,
-
-    yields a tuple with filename, task name, time in seconds.
-
-    Parameters
-    ----------
-    filename :
-
-    name :
-         (Default value = "")
-    setup :
-         (Default value = "")
-    number :
-         (Default value = 0)
-    repeat :
-         (Default value = 3)
-
-    Returns
-    -------
-
-    """
-    with open(filename, "r") as fp:
-        tasks = yaml.load(fp)
-
-    for task in tasks:
-        new_task = build_task(task, name, setup, number, repeat)
-        for task_name, value in time_task(**new_task):
-            yield task_name, value
-
-
-def recursive_glob(rootdir=".", pattern="*"):
-    return [
-        os.path.join(looproot, filename)
-        for looproot, _, filenames in os.walk(rootdir)
-        for filename in filenames
-        if fnmatch.fnmatch(filename, pattern)
-    ]
-
-
-def main(filenames=None):
-    if not filenames:
-        filenames = recursive_glob(".", "bench_*.yaml")
-    elif isinstance(filenames, str):
-        filenames = [filenames]
-
-    for filename in filenames:
-        print(filename)
-        print("-" * len(filename))
-        print()
-        for task_name, value in time_file(filename):
-            print(f"{value:.2e}   {task_name}")
-        print()
-
-
-if __name__ == "__main__":
-    main()
diff --git a/bench/bench_base.yaml b/bench/bench_base.yaml
deleted file mode 100644
index f767a04..0000000
--- a/bench/bench_base.yaml
+++ /dev/null
@@ -1,42 +0,0 @@
-
-
-- name: importing
-  stmt: import pint
-
-- name: empty registry
-  setup: import pint
-  stmt: ureg = pint.UnitRegistry(None)
-
-- name: default registry
-  setup: import pint
-  stmt: ureg = pint.UnitRegistry()
-
-- name: finding meter
-  setup: |
-         import pint
-         ureg = pint.UnitRegistry()
-  stmts:
-    - name: (attr)
-      stmt: q = ureg.meter
-    - name: (item)
-      stmt: q = ureg['meter']
-
-- name: base units
-  setup: |
-         import pint
-         ureg = pint.UnitRegistry()
-  stmts:
-    - name: meter
-      stmt: ureg.get_base_units('meter')
-    - name: yard
-      stmt: ureg.get_base_units('yard')
-    - name: meter / second
-      stmt: ureg.get_base_units('meter / second')
-    - name: yard / minute
-      stmt: ureg.get_base_units('yard / minute')
-
-- name: build cache
-  setup: |
-         import pint
-         ureg = pint.UnitRegistry()
-  stmt: ureg._build_cache()
diff --git a/bench/bench_numpy.yaml b/bench/bench_numpy.yaml
deleted file mode 100644
index 8609bc0..0000000
--- a/bench/bench_numpy.yaml
+++ /dev/null
@@ -1,23 +0,0 @@
-
-
-- name: NumPy
-  setup: |
-          import numpy as np
-          import pint
-          ureg = pint.UnitRegistry()
-  stmts:
-    - name: cosine
-      setup: |
-              d = np.arange(0, 90, 10)
-              r = np.deg2rad(d)
-      base: np.cos(r)
-      stmts:
-        - name: radian
-          setup: x = r * ureg.radian
-          stmt: np.cos(x)
-        - name: dimensionless
-          setup: x = r * ureg.dimensionless
-          stmt: np.cos(x)
-        - name: degree
-          setup: x = d * ureg.degree
-          stmt: np.cos(x)
diff --git a/benchmarks/00_common.py b/benchmarks/00_common.py
new file mode 100644
index 0000000..261cea9
--- /dev/null
+++ b/benchmarks/00_common.py
@@ -0,0 +1,2 @@
+def time_import():
+    import pint  # noqa: F401
diff --git a/benchmarks/01_registry_creation.py b/benchmarks/01_registry_creation.py
new file mode 100644
index 0000000..e555585
--- /dev/null
+++ b/benchmarks/01_registry_creation.py
@@ -0,0 +1,10 @@
+import pint
+
+from . import util
+
+
+def time_create_registry(args):
+    pint.UnitRegistry(*args)
+
+
+time_create_registry.params = [[(None,), tuple(), (util.get_tiny_def(),)]]
diff --git a/benchmarks/10_registry.py b/benchmarks/10_registry.py
new file mode 100644
index 0000000..d95a53f
--- /dev/null
+++ b/benchmarks/10_registry.py
@@ -0,0 +1,101 @@
+import pint
+
+from . import util
+
+units = ("meter", "kilometer", "second", "minute", "angstrom")
+
+other_units = ("meter", "angstrom", "kilometer/second", "angstrom/minute")
+
+all_values = ("int", "float", "complex")
+
+ureg = None
+data = {}
+
+
+def setup(*args):
+
+    global ureg, data
+
+    data["int"] = 1
+    data["float"] = 1.0
+    data["complex"] = complex(1, 2)
+
+    ureg = pint.UnitRegistry(util.get_tiny_def())
+
+
+def my_setup(*args):
+    global data
+    setup(*args)
+    for unit in units + other_units:
+        data["uc_%s" % unit] = pint.registry.to_units_container(unit, ureg)
+
+
+def time_build_cache():
+    ureg._build_cache()
+
+
+def time_getattr(key):
+    getattr(ureg, key)
+
+
+time_getattr.params = units
+
+
+def time_getitem(key):
+    ureg[key]
+
+
+time_getitem.params = units
+
+
+def time_parse_unit_name(key):
+    ureg.parse_unit_name(key)
+
+
+time_parse_unit_name.params = units
+
+
+def time_parse_units(key):
+    ureg.parse_units(key)
+
+
+time_parse_units.params = units
+
+
+def time_parse_expression(key):
+    ureg.parse_expression("1.0 " + key)
+
+
+time_parse_expression.params = units
+
+
+def time_base_units(unit):
+    ureg.get_base_units(unit)
+
+
+time_base_units.params = other_units
+
+
+def time_to_units_container_registry(unit):
+    pint.registry.to_units_container(unit, ureg)
+
+
+time_to_units_container_registry.params = other_units
+
+
+def time_to_units_container_detached(unit):
+    pint.registry.to_units_container(unit, ureg)
+
+
+time_to_units_container_detached.params = other_units
+
+
+def time_convert_from_uc(key):
+    src, dst = key
+    ureg._convert(1.0, data[src], data[dst])
+
+
+time_convert_from_uc.setup = my_setup
+time_convert_from_uc.params = [
+    (("uc_meter", "uc_kilometer"), ("uc_kilometer/second", "uc_angstrom/minute"))
+]
diff --git a/benchmarks/20_quantity.py b/benchmarks/20_quantity.py
new file mode 100644
index 0000000..5f6dd41
--- /dev/null
+++ b/benchmarks/20_quantity.py
@@ -0,0 +1,56 @@
+import itertools as it
+import operator
+
+import pint
+
+from . import util
+
+units = ("meter", "kilometer", "second", "minute", "angstrom")
+all_values = ("int", "float", "complex")
+all_values_q = tuple(
+    "%s_%s" % (a, b) for a, b in it.product(all_values, ("meter", "kilometer"))
+)
+
+op1 = (operator.neg, operator.truth)
+op2_cmp = (operator.eq,)  # operator.lt)
+op2_math = (operator.add, operator.sub, operator.mul, operator.truediv)
+
+ureg = None
+data = {}
+
+
+def setup(*args):
+
+    global ureg, data
+
+    data["int"] = 1
+    data["float"] = 1.0
+    data["complex"] = complex(1, 2)
+
+    ureg = pint.UnitRegistry(util.get_tiny_def())
+
+    for key in all_values:
+        data[key + "_meter"] = data[key] * ureg.meter
+        data[key + "_kilometer"] = data[key] * ureg.kilometer
+
+
+def time_build_by_mul(key):
+    data[key] * ureg.meter
+
+
+time_build_by_mul.params = all_values
+
+
+def time_op1(key, op):
+    op(data[key])
+
+
+time_op1.params = [all_values_q, op1]
+
+
+def time_op2(keys, op):
+    key1, key2 = keys
+    op(data[key1], data[key2])
+
+
+time_op2.params = [tuple(it.product(all_values_q, all_values_q)), op2_math + op2_cmp]
diff --git a/benchmarks/30_numpy.py b/benchmarks/30_numpy.py
new file mode 100644
index 0000000..ec83833
--- /dev/null
+++ b/benchmarks/30_numpy.py
@@ -0,0 +1,97 @@
+import itertools as it
+import operator
+
+import numpy as np
+
+import pint
+
+from . import util
+
+lengths = ("short", "mid")
+all_values = tuple(
+    "%s_%s" % (a, b) for a, b in it.product(lengths, ("list", "tuple", "array"))
+)
+all_arrays = ("short_array", "mid_array")
+units = ("meter", "kilometer")
+all_arrays_q = tuple("%s_%s" % (a, b) for a, b in it.product(all_arrays, units))
+
+ureg = None
+data = {}
+op1 = (operator.neg,)  # operator.truth,
+op2_cmp = (operator.eq, operator.lt)
+op2_math = (operator.add, operator.sub, operator.mul, operator.truediv)
+numpy_op2_cmp = (np.equal, np.less)
+numpy_op2_math = (np.add, np.subtract, np.multiply, np.true_divide)
+
+
+def float_range(n):
+    return (float(x) for x in range(1, n + 1))
+
+
+def setup(*args):
+
+    global ureg, data
+    short = list(float_range(3))
+    mid = list(float_range(1_000))
+
+    data["short_list"] = short
+    data["short_tuple"] = tuple(short)
+    data["short_array"] = np.asarray(short)
+    data["mid_list"] = mid
+    data["mid_tuple"] = tuple(mid)
+    data["mid_array"] = np.asarray(mid)
+
+    ureg = pint.UnitRegistry(util.get_tiny_def())
+
+    for key in all_arrays:
+        data[key + "_meter"] = data[key] * ureg.meter
+        data[key + "_kilometer"] = data[key] * ureg.kilometer
+
+
+def time_finding_meter_getattr():
+    ureg.meter
+
+
+def time_finding_meter_getitem():
+    ureg["meter"]
+
+
+def time_base_units(unit):
+    ureg.get_base_units(unit)
+
+
+time_base_units.params = ["meter", "angstrom", "meter/second", "angstrom/minute"]
+
+
+def time_build_by_mul(key):
+    data[key] * ureg.meter
+
+
+time_build_by_mul.params = all_arrays
+
+
+def time_op1(key, op):
+    op(data[key])
+
+
+time_op1.params = [all_arrays_q, op1 + (np.sqrt, np.square)]
+
+
+def time_op2(keys, op):
+    key1, key2 = keys
+    op(data[key1], data[key2])
+
+
+time_op2.params = [
+    (
+        ("short_array_meter", "short_array_meter"),
+        ("short_array_meter", "short_array_kilometer"),
+        ("short_array_kilometer", "short_array_meter"),
+        ("short_array_kilometer", "short_array_kilometer"),
+        ("mid_array_meter", "mid_array_meter"),
+        ("mid_array_meter", "mid_array_kilometer"),
+        ("mid_array_kilometer", "mid_array_meter"),
+        ("mid_array_kilometer", "mid_array_kilometer"),
+    ),
+    op2_math + op2_cmp + numpy_op2_math + numpy_op2_cmp,
+]
diff --git a/benchmarks/__init__.py b/benchmarks/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/benchmarks/__init__.py
diff --git a/benchmarks/util.py b/benchmarks/util.py
new file mode 100644
index 0000000..4e72048
--- /dev/null
+++ b/benchmarks/util.py
@@ -0,0 +1,38 @@
+import io
+
+SMALL_VEC_LEN = 3
+MID_VEC_LEN = 1_000
+LARGE_VEC_LEN = 1_000_000
+
+TINY_DEF = """
+yocto- = 1e-24 = y-
+zepto- = 1e-21 = z-
+atto- =  1e-18 = a-
+femto- = 1e-15 = f-
+pico- =  1e-12 = p-
+nano- =  1e-9  = n-
+micro- = 1e-6  = µ- = u-
+milli- = 1e-3  = m-
+centi- = 1e-2  = c-
+deci- =  1e-1  = d-
+deca- =  1e+1  = da- = deka-
+hecto- = 1e2   = h-
+kilo- =  1e3   = k-
+mega- =  1e6   = M-
+giga- =  1e9   = G-
+tera- =  1e12  = T-
+peta- =  1e15  = P-
+exa- =   1e18  = E-
+zetta- = 1e21  = Z-
+yotta- = 1e24  = Y-
+
+meter = [length] = m = metre
+second = [time] = s = sec
+
+angstrom = 1e-10 * meter = Å = ångström = Å
+minute = 60 * second = min
+"""
+
+
+def get_tiny_def():
+    return io.StringIO(TINY_DEF)
diff --git a/docs/numpy.ipynb b/docs/numpy.ipynb
index fa987b2..5edf125 100644
--- a/docs/numpy.ipynb
+++ b/docs/numpy.ipynb
@@ -203,7 +203,7 @@
     "- **Math operations**: `add`, `subtract`, `multiply`, `divide`, `logaddexp`, `logaddexp2`, `true_divide`, `floor_divide`, `negative`, `remainder`, `mod`, `fmod`, `absolute`, `rint`, `sign`, `conj`, `exp`, `exp2`, `log`, `log2`, `log10`, `expm1`, `log1p`, `sqrt`, `square`, `cbrt`, `reciprocal`\n",
     "- **Trigonometric functions**: `sin`, `cos`, `tan`, `arcsin`, `arccos`, `arctan`, `arctan2`, `hypot`, `sinh`, `cosh`, `tanh`, `arcsinh`, `arccosh`, `arctanh`\n",
     "- **Comparison functions**: `greater`, `greater_equal`, `less`, `less_equal`, `not_equal`, `equal`\n",
-    "- **Floating functions**: `isreal`, `iscomplex`, `isfinite`, `isinf`, `isnan`, `signbit`, `copysign`, `nextafter`, `modf`, `ldexp`, `frexp`, `fmod`, `floor`, `ceil`, `trunc`\n",
+    "- **Floating functions**: `isreal`, `iscomplex`, `isfinite`, `isinf`, `isnan`, `signbit`, `sign`, `copysign`, `nextafter`, `modf`, `ldexp`, `frexp`, `fmod`, `floor`, `ceil`, `trunc`\n",
     "\n",
     "And the following NumPy functions:"
    ]
@@ -500,4 +500,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 4
-}
+}
\ No newline at end of file
diff --git a/pint/numpy_func.py b/pint/numpy_func.py
index 0f220b0..bcf406a 100644
--- a/pint/numpy_func.py
+++ b/pint/numpy_func.py
@@ -339,7 +339,7 @@ Define ufunc behavior collections.
 - `op_units_output_ufuncs`: determine output unit from input unit as determined by
   operation (see `get_op_output_unit`)
 """
-strip_unit_input_output_ufuncs = ["isnan", "isinf", "isfinite", "signbit"]
+strip_unit_input_output_ufuncs = ["isnan", "isinf", "isfinite", "signbit", "sign"]
 matching_input_bare_output_ufuncs = [
     "equal",
     "greater",
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index e39b01a..0bb7cae 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -783,6 +783,12 @@ class TestIssues(QuantityTestCase):
         self.assertIsInstance(foo1, foo2.__class__)
         self.assertIsInstance(foo2, foo1.__class__)
 
+    @helpers.requires_numpy()
+    def test_issue1174(self):
+        q = [1.0, -2.0, 3.0, -4.0] * self.ureg.meter
+        self.assertTrue(np.sign(q[0].magnitude))
+        self.assertTrue(np.sign(q[1].magnitude))
+
 
 if np is not None: