use np.maximum() instead of boolean indexing. (#350)

* use np.maximum() instead of boolean indexing.

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docs/notebooks/03_Extracting_forcing_data.ipynb

@@ -26,6 +26,7 @@
     "\n",
     "import fsspec  # noqa\n",
     "import intake\n",
+    "import numpy as np\n",
     "import s3fs  # noqa\n",
     "import xarray as xr\n",
     "from clisops.core import subset\n",
@@ -207,7 +208,7 @@
     "    ERA5_pr = ERA5_pr.mean({\"latitude\", \"longitude\"})\n",
     "\n",
     "    # Ensure that the precipitation is non-negative, which can happen with some reanalysis models.\n",
-    "    ERA5_pr[ERA5_pr < 0] = 0\n",
+    "    ERA5_pr = np.maximum(ERA5_pr, 0)\n",
     "\n",
     "    # Transform them to a dataset such that they can be written with attributes to netcdf\n",
     "    ERA5_tmin = ERA5_tmin.to_dataset(name=\"tmin\", promote_attrs=True)\n",
@@ -282,7 +283,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.16"
+   "version": "3.10.13"
   },
   "nbdime-conflicts": {
    "local_diff": [