DOC: Link plot-heatmaps in the tutorial

Author: kernc

backtesting/lib.py

@@ -123,12 +123,15 @@ def plot_heatmaps(heatmap: pd.Series,
                   open_browser: bool = True):
     """
     Plots a grid of heatmaps, one for every pair of parameters in `heatmap`.
+    See example in [the tutorial].
+
+    [the tutorial]: https://kernc.github.io/backtesting.py/doc/examples/Parameter%20Heatmap%20&%20Optimization.html#plot-heatmap  # noqa: E501
 
     `heatmap` is a Series as returned by
     `backtesting.backtesting.Backtest.optimize` when its parameter
     `return_heatmap=True`.
 
-    When projecting the n-dimensional heatmap onto 2D, the values are
+    When projecting the n-dimensional (n > 2) heatmap onto 2D, the values are
     aggregated by 'max' function by default. This can be tweaked
     with `agg` parameter, which accepts any argument pandas knows
     how to aggregate by.
@@ -491,7 +494,7 @@ def next(self):
 
 class FractionalBacktest(Backtest):
     """
-    A `backtesting.Backtest` that supports fractional share trading
+    A `backtesting.backtesting.Backtest` that supports fractional share trading
     by simple composition. It applies roughly the transformation:
 
         df = (df / satoshi).assign(Volume=df.Volume * satoshi)

doc/examples/Parameter Heatmap & Optimization.ipynb

@@ -846,7 +846,9 @@
     "Since our strategy contains several parameters, we might be interested in other relationships between their values.\n",
     "We can use\n",
     "[`backtesting.lib.plot_heatmaps()`](https://kernc.github.io/backtesting.py/doc/backtesting/lib.html#backtesting.lib.plot_heatmaps)\n",
-    "function to plot interactive heatmaps of all parameter combinations simultaneously."
+    "function to plot interactive heatmaps of all parameter combinations simultaneously.\n",
+    "\n",
+    "<a id=plot-heatmaps></a>"
    ]
   },
   {

doc/examples/Parameter Heatmap & Optimization.py

@@ -160,6 +160,8 @@ def next(self):
 # We can use
 # [`backtesting.lib.plot_heatmaps()`](https://kernc.github.io/backtesting.py/doc/backtesting/lib.html#backtesting.lib.plot_heatmaps)
 # function to plot interactive heatmaps of all parameter combinations simultaneously.
+#
+# <a id=plot-heatmaps></a>
 
 # +
 from backtesting.lib import plot_heatmaps