Area with `y2` triggers ununderstandable ndarray VisibleDeprecationWarning

ALL software version info

# Name                    Version                   Build  Channel
hvplot                    0.7.0              pyhd3deb0d_0    conda-forge
# packages in environment at /home/maye/miniconda3/envs/py38:
#
# Name                    Version                   Build  Channel
bokeh                     2.2.3            py38h578d9bd_0    conda-forge
# packages in environment at /home/maye/miniconda3/envs/py38:
#
# Name                    Version                   Build  Channel
ipython                   7.19.0           py38h81c977d_2    conda-forge
ipython_genutils          0.2.0                      py_1    conda-forge
jupyter-lsp-python        1.1.1              pyhd8ed1ab_0    conda-forge
msgpack-python            1.0.2            py38h1fd1430_1    conda-forge
python                    3.8.6           hffdb5ce_4_cpython    conda-forge
python-dateutil           2.8.1                      py_0    conda-forge
python-jsonrpc-server     0.4.0              pyh9f0ad1d_0    conda-forge
python-language-server    0.36.2             pyhd8ed1ab_0    conda-forge
python_abi                3.8                      1_cp38    conda-forge
# packages in environment at /home/maye/miniconda3/envs/py38:
#
# Name                    Version                   Build  Channel
notebook                  6.2.0            py38h578d9bd_0    conda-forge
# packages in environment at /home/maye/miniconda3/envs/py38:
#
# Name                    Version                   Build  Channel
jupyter                   1.0.0            py38h578d9bd_6    conda-forge
jupyter-lsp               1.1.1              pyhd8ed1ab_0    conda-forge
jupyter-lsp-python        1.1.1              pyhd8ed1ab_0    conda-forge
jupyter_client            6.1.11             pyhd8ed1ab_1    conda-forge
jupyter_console           6.2.0                      py_0    conda-forge
jupyter_core              4.7.0            py38h578d9bd_1    conda-forge
jupyter_server            1.2.2            py38h578d9bd_1    conda-forge
jupyterlab                3.0.6              pyhd8ed1ab_0    conda-forge
jupyterlab-lsp            3.2.0              pyhd8ed1ab_0    conda-forge
jupyterlab_code_formatter 1.4.2              pyhd8ed1ab_0    conda-forge
jupyterlab_pygments       0.1.2              pyh9f0ad1d_0    conda-forge
jupyterlab_server         2.1.3              pyhd8ed1ab_0    conda-forge
jupyterlab_widgets        1.0.0              pyhd8ed1ab_1    conda-forge

Description of expected behavior and the observed behavior

Because I am doing a lot of these plots I get a ton of these warnings. A first work-around would be a way to suppress them. I expect no error because all my arrays are of the same length, no column or arrays are staggered with tuples or something like that (like [arr1, (arr2, 1)]…

Use of the y2 option triggers an ndarray VisibleDeprecationWarning about ragged sequences but there are none on the user’s side, so I presume the issue with an hvplot helper routine in core/util.py.

Complete, minimal, self-contained example code that reproduces the issue

testdf = pd.DataFrame(np.random.rand(100), columns=["a"])
testdf['b'] = testdf['a']+2
testdf.hvplot.area(x='index', y='a', y2='b')

Stack traceback and/or browser JavaScript console output

/home/maye/miniconda3/envs/py38/lib/python3.8/site-packages/holoviews/core/util.py:980: VisibleDeprecationWarning: Creating an ndarray from ragged nested sequences (which is a list-or-tuple of lists-or-tuples-or ndarrays with different lengths or shapes) is deprecated. If you meant to do this, you must specify ‘dtype=object’ when creating the ndarray arr = np.array(values)

Screenshots or screencasts of the bug in action

[philippjfr]

v1.14.1 is old, we are tagging v1.14.2 in the next 5 mins.

[michaelaye]

Sorry, should have looked at the ChangeLog.