[DO NOT MERGE] Integration: PR backlog

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "spatialmath-python"
-version = "1.1.18"
+version = "1.1.19"
 authors = [
   { name="Peter Corke", email="rvc@petercorke.com" },
 ]
@@ -78,7 +78,7 @@ ros-humble = [
 
 [build-system]
 
-requires = ["setuptools", "oldest-supported-numpy"]
+requires = ["setuptools"]
 build-backend = "setuptools.build_meta"
 
 [tool.setuptools]

spatialmath/base/__init__.py

@@ -10,6 +10,7 @@
 from spatialmath.base.vectors import *  # lgtm [py/polluting-import]
 from spatialmath.base.symbolic import *  # lgtm [py/polluting-import]
 from spatialmath.base.numeric import *  # lgtm [py/polluting-import]
+from spatialmath.base._environment import *  # lgtm [py/polluting-import]
 
 import importlib
 
@@ -46,7 +47,6 @@
     "plotvol2": "graphics",
     "plotvol3": "graphics",
     "expand_dims": "graphics",
-    "isnotebook": "graphics",
 }
 
 
@@ -394,6 +394,7 @@ def __getattr__(name):
     "axes_logic",
     "set_window_title",
     "expand_dims",
+    "environment",
     "isnotebook",
     # spatial.base.numeric
     "numjac",

spatialmath/base/_environment.py

@@ -0,0 +1,78 @@
+# Part of Spatial Math Toolbox for Python
+# Copyright (c) 2000 Peter Corke
+# MIT Licence, see details in top-level file: LICENCE
+
+"""
+Detect the interactive environment that Python is running in.
+
+This module deliberately does not import Matplotlib, so it is cheap to import
+and works when Matplotlib is not installed.
+"""
+
+import sys
+from typing import Literal
+
+__all__ = ["environment", "isnotebook"]
+
+Environment = Literal["terminal", "ipython", "jupyter", "colab", "jupyterlite"]
+
+
+def environment() -> Environment:
+    """
+    Determine the environment that Python is running in
+
+    :return: the environment
+    :rtype: str
+
+    The result is one of:
+
+    ========================  ====================================================
+    ``"terminal"``            standard Python interpreter, or script
+    ``"ipython"``             IPython running in a terminal
+    ``"jupyter"``             Jupyter kernel, eg. JupyterLab, Notebook, VS Code or
+                              qtconsole
+    ``"colab"``               Google Colab
+    ``"jupyterlite"``         JupyterLite, running in the browser (Pyodide)
+    ========================  ====================================================
+
+    .. note:: The different Jupyter front ends (JupyterLab, classic Notebook,
+        VS Code, Jupyter Desktop) cannot be reliably told apart from within the
+        kernel, so all are reported as ``"jupyter"``.  How figures will be
+        rendered depends on the Matplotlib backend, not on the front end.
+
+    :seealso: :func:`isnotebook`
+    """
+    # Colab and JupyterLite both also provide an IPython kernel, so test for
+    # them first
+    if "google.colab" in sys.modules:
+        return "colab"
+    if sys.platform == "emscripten":
+        return "jupyterlite"
+
+    try:
+        shell = get_ipython().__class__.__name__  # type: ignore[name-defined]
+    except NameError:
+        return "terminal"  # probably standard Python interpreter
+
+    if shell == "ZMQInteractiveShell":
+        return "jupyter"  # Jupyter notebook or qtconsole
+    elif shell == "TerminalInteractiveShell":
+        return "ipython"
+    else:
+        return "terminal"  # other type (?)
+
+
+def isnotebook() -> bool:
+    """
+    Determine if code is being run from a Jupyter notebook
+
+    :return: True if running in a Jupyter kernel, Google Colab or JupyterLite
+    :rtype: bool
+
+    :seealso: :func:`environment`
+
+    :references:
+
+        - https://stackoverflow.com/questions/15411967/how-can-i-check-if-code-is-executed-in-the-ipython-notebook/39662359#39662359
+    """
+    return environment() in ("jupyter", "colab", "jupyterlite")

spatialmath/base/argcheck.py

@@ -16,10 +16,10 @@
 from collections.abc import Iterable
 
 # from spatialmath.base import symbolic as sym # HACK
-from spatialmath.base.symbolic import issymbol, symtype
+from spatialmath.base.symbolic import issymbol
 
 # valid scalar types
-_scalartypes = (int, np.integer, float, np.floating) + symtype
+_scalartypes = (int, np.integer, float, np.floating)
 
 # from typing import Union, List, Tuple, Any, Optional, Type, Callable
 # from numpy.typing import DTypeLike
@@ -47,7 +47,9 @@ def isscalar(x: Any) -> bool:
         >>> isscalar([1])
 
     """
-    return isinstance(x, _scalartypes)
+    return isinstance(x, _scalartypes) or (
+        not isinstance(x, (list, tuple)) and issymbol(x)
+    )
 
 
 def isinteger(x: Any) -> bool:
@@ -386,7 +388,7 @@ def getvector(
     """
     dt = dtype
 
-    if isinstance(v, _scalartypes):  # handle scalar case
+    if isscalar(v):  # handle scalar case
         v = [v]  # type: ignore
     if isinstance(v, (list, tuple)):
         # list or tuple was passed in
@@ -501,7 +503,7 @@ def isvector(v: Any, dim: Optional[int] = None) -> bool:
     if (
         isinstance(v, (list, tuple))
         and (dim is None or len(v) == dim)
-        and all(map(lambda x: isinstance(x, _scalartypes), v))
+        and all(map(isscalar, v))
     ):
         return True  # list or tuple
 
@@ -516,7 +518,7 @@ def isvector(v: Any, dim: Optional[int] = None) -> bool:
         else:
             return s == (dim,) or s == (1, dim) or s == (dim, 1)
 
-    if (dim is None or dim == 1) and isinstance(v, _scalartypes):
+    if (dim is None or dim == 1) and isscalar(v):
         return True
 
     return False
@@ -620,11 +622,7 @@ def isnumberlist(x: Any) -> bool:
         >>> isnumberlist(np.r_[1,2])
     """
 
-    return (
-        isinstance(x, (list, tuple))
-        and len(x) > 0
-        and all(map(lambda x: isinstance(x, _scalartypes), x))
-    )
+    return isinstance(x, (list, tuple)) and len(x) > 0 and all(map(isscalar, x))
 
 
 def isvectorlist(x: Any, n: int) -> bool:

spatialmath/base/graphics.py

@@ -1513,7 +1513,10 @@ def _axes_dimensions(ax: plt.Axes) -> int:
             # handle the case of Animate objects pretending to be Axes
             classname = ax.__class__.__name__
             base_classes = ax.__class__.__bases__
-            if classname in ("Axes3DSubplot", "Animate") or any(base_class.__name__ in ("Axes3DSubplot", "Animate") for base_class in base_classes):
+            if classname in ("Axes3DSubplot", "Animate") or any(
+                base_class.__name__ in ("Axes3DSubplot", "Animate")
+                for base_class in base_classes
+            ):
                 return 3
             elif classname in ("AxesSubplot", "Animate2"):
                 return 2
@@ -1580,6 +1583,7 @@ def axes_logic(
         """
 
         # print(f"new axis logic ({dimensions}D): ", end='')
+        use_current_figure = False
         if ax is None:
             # no axes passed in, find out what's happening
             # need to be careful to not use gcf() or gca() since they
@@ -1597,6 +1601,10 @@ def axes_logic(
                     # print(f"ax has {_axes_dimensions(ax)} dimensions")
                     if _axes_dimensions(ax) == dimensions and not new:
                         return ax
+                elif not new:
+                    # the current figure is empty, eg. from a bare plt.figure():
+                    # put the axes in it rather than leave it empty and make another
+                    use_current_figure = True
             # otherwise it doesnt exist or dimension mismatch, create new axes
         else:
             # print("ax given", ax)
@@ -1607,7 +1615,8 @@ def axes_logic(
                 return ax
             # print("mismatch in dimensions, create new axes")
         # print("create new axes")
-        plt.figure()
+        if not use_current_figure:
+            plt.figure()
         if dimensions == 2:
             ax = plt.axes()
             if autoscale:
@@ -1736,20 +1745,24 @@ def plotvol3(
         ax._plotvol = True
         return ax
 
-    def expand_dims(dim: ArrayLike = None, nd: int = 2) -> NDArray:
+    def expand_dims(dim: ArrayLike | None = None, nd: int = 2) -> NDArray | None:
         """
         Expand compact axis dimensions
 
-        :param dim: dimensions, defaults to None
+        :param dim: dimensions, or None if unspecified, defaults to None
         :type dim: scalar, array_like(2), array_like(4), array_like(6), optional
-        :param nd: number of axes dimensions, defaults to 2
+        :param nd: number of axes dimensions (2 or 3), defaults to 2
         :type nd: int, optional
         :raises ValueError: bad arguments
-        :return: 2d or 3d dimensions vector
-        :rtype: ndarray(4) or ndarray(6)
+        :return: 2d or 3d dimensions vector, or None if unspecified
+        :rtype: ndarray(4), ndarray(6), or None
 
         Compute bounding dimensions for plots from shorthand notation.
 
+        ``None`` is returned unchanged so the caller can choose whether to
+        autoscale or obtain dimensions from another source. No default extent
+        is inferred.
+
         If ``nd==2``, [xmin, xmax, ymin, ymax]:
             * A -> [-A, A, -A, A]
             * [A,B] -> [A, B, A, B]
@@ -1766,6 +1779,11 @@ def expand_dims(dim: ArrayLike = None, nd: int = 2) -> NDArray:
         corresponding maximum, matplotlib will invert that axis when the limits
         are applied, which is a convenient way to flip an axis direction.
         """
+        if nd not in (2, 3):
+            raise ValueError("nd is 2 or 3")
+        if dim is None:
+            return None
+
         dim = smb.getvector(dim)
 
         if nd == 2:
@@ -1788,8 +1806,6 @@ def expand_dims(dim: ArrayLike = None, nd: int = 2) -> NDArray:
                 return dim
             else:
                 raise ValueError("bad dimension specified")
-        else:
-            raise ValueError("nd is 2 or 3")
 
     def set_window_title(fig: plt.Figure, title: str) -> bool:
         """
@@ -1822,26 +1838,6 @@ def set_window_title(fig: plt.Figure, title: str) -> bool:
             return True
         return False
 
-    def isnotebook() -> bool:
-        """
-        Determine if code is being run from a Jupyter notebook
-
-        :references:
-
-            - https://stackoverflow.com/questions/15411967/how-can-i-check-if-code-
-            is-executed-in-the-ipython-notebook/39662359#39662359
-        """
-        try:
-            shell = get_ipython().__class__.__name__
-            if shell == "ZMQInteractiveShell":
-                return True  # Jupyter notebook or qtconsole
-            elif shell == "TerminalInteractiveShell":
-                return False  # Terminal running IPython
-            else:
-                return False  # Other type (?)
-        except NameError:
-            return False  # Probably standard Python interpreter
-
     if __name__ == "__main__":
         import pathlib
 

spatialmath/base/quaternions.py

@@ -16,11 +16,13 @@
 import spatialmath.base as smb
 from spatialmath.base.argcheck import getunit
 from spatialmath.base.types import *
-import scipy.interpolate as interpolate
-from typing import Optional
+from typing import TYPE_CHECKING, Optional
 from functools import lru_cache
 import warnings
 
+if TYPE_CHECKING:
+    import scipy.interpolate as interpolate
+
 _eps = np.finfo(np.float64).eps
 
 
@@ -920,7 +922,7 @@ def _compute_cdf_sin_squared(theta: float):
 @lru_cache(maxsize=1)
 def _generate_inv_cdf_sin_squared_interp(
     num_interpolation_points: int = 256,
-) -> interpolate.interp1d:
+) -> "interpolate.interp1d":
     """
     Computes an interpolation function for the inverse CDF of the distribution of angular magnitude.
 
@@ -933,6 +935,8 @@ def _generate_inv_cdf_sin_squared_interp(
     This function returns interpolation function for the inverse of the integral of the
     pdf of angular magnitudes (2/pi * sin^2(theta/2)), which is not analytically defined.
     """
+    import scipy.interpolate as interpolate  # deferred, it is slow to import
+
     cdf_sin_squared_interp_angles = np.linspace(0, np.pi, num_interpolation_points)
     cdf_sin_squared_interp_values = _compute_cdf_sin_squared(
         cdf_sin_squared_interp_angles