checkpoint: partial dev

Author: DanielGoldfarb

src/mplfinance/_arg_validators.py

@@ -5,6 +5,8 @@
 from   mplfinance._helpers import _list_of_dict
 import matplotlib as mpl
 import warnings
+from   mplfinance._utils import _date_to_mdate
+from   mplfinance._utils import _date_to_iloc_extrapolate
 
 def _check_and_prepare_data(data, config):
     '''
@@ -76,6 +78,28 @@ def _check_and_prepare_data(data, config):
 
     return dates, opens, highs, lows, closes, volumes
 
+def _check_and_convert_xlim_configuration(data, config):
+    '''
+    Check, if user entered `xlim` kwarg, if user entered dates
+    then we may need to convert them to iloc or matplotlib dates.
+    '''
+    if config['xlim'] is None:
+        return None
+
+    xlim = config['xlim']
+
+    if not _xlim_validator(xlim):
+        raise ValueError('Bad xlim configuration #1')
+
+    if all([_is_date_like(dt) for dt in xlim]):
+        if config['show_nontrading']:
+            xlim = [ _date_to_mdate(dt) for dt in xlim]
+        else
+            xlim = [ _date_to_iloc_extrapolate(data.index.to_series(),dt) for dt in xlim]
+        
+    return xlim
+
+
 def _get_valid_plot_types(plottype=None):
 
     _alias_types = {
@@ -140,6 +164,11 @@ def _is_datelike(value):
             return False
     return False
 
+def _xlim_validator(value):
+    return (isinstance(value, (list,tuple)) and len(value) == 2
+            and (all([isinstance(v,(int,float)) for v in value])
+                 or all([_is_date_like(v) for v in value])))
+
 def _vlines_validator(value):
     '''Validate `vlines` kwarg value:  must be "datelike" or sequence of "datelike"
     '''

src/mplfinance/_utils.py

@@ -194,6 +194,26 @@ def _date_to_iloc(dtseries,date):
     if isinstance(loc2,slice): loc2 = loc2.stop - 1
     return (loc1+loc2)/2.0
 
+def _date_to_iloc_extrapolate(dtseries,date):
+    d1s = dtseries.loc[date:]
+    if len(d1s) < 1:
+        # xtrapolate forward:
+        pass
+    d1 = d1s.index[0]
+    d2s = dtseries.loc[:date]
+    if len(d2s) < 1:
+        # extrapolate backward:
+        pass
+    d2 = dtseries.loc[:date].index[-1]
+    # If there are duplicate dates in the series, for example in a renko plot
+    # then .get_loc(date) will return a slice containing all the dups, so:
+    loc1 = dtseries.index.get_loc(d1)
+    if isinstance(loc1,slice): loc1 = loc1.start
+    loc2 = dtseries.index.get_loc(d2)
+    if isinstance(loc2,slice): loc2 = loc2.stop - 1
+    return (loc1+loc2)/2.0
+
+
 def _date_to_mdate(date):
     if isinstance(date,str):
         pydt = pd.to_datetime(date).to_pydatetime()

src/mplfinance/plotting.py

@@ -37,6 +37,7 @@
 from mplfinance._arg_validators import _alines_validator, _tlines_validator
 from mplfinance._arg_validators import _scale_padding_validator, _yscale_validator
 from mplfinance._arg_validators import _valid_panel_id, _check_for_external_axes
+from mplfinance._arg_validators import _xlim_validator
 
 from mplfinance._panels import _build_panels
 from mplfinance._panels import _set_ticks_on_bottom_panel_only
@@ -185,8 +186,7 @@ def _valid_plot_kwargs():
                                                                       and all([isinstance(v,(int,float)) for v in value])},
 
         'xlim'                      : {'Default'      : None,
-                                       'Validator'    : lambda value: isinstance(value, (list,tuple)) and len(value) == 2 
-                                                                      and all([isinstance(v,(int,float)) for v in value])},
+                                       'Validator'    : lambda value: _xlim_validator(value) },
 
         'set_ylim_panelB'           : {'Default'      : None,
                                        'Validator'    : lambda value: _warn_set_ylim_deprecated(value) },
@@ -295,6 +295,8 @@ def plot( data, **kwargs ):
 
     dates,opens,highs,lows,closes,volumes = _check_and_prepare_data(data, config)
 
+    config['xlim'] = _check_and_convert_xlim_configuration(data, config)
+
     if config['type'] in VALID_PMOVE_TYPES and config['addplot'] is not None:
         err = "`addplot` is not supported for `type='" + config['type'] +"'`"
         raise ValueError(err)
@@ -363,7 +365,7 @@ def plot( data, **kwargs ):
         panels = _build_panels(fig, config)
         volumeAxes = panels.at[config['volume_panel'],'axes'][0] if config['volume'] is True else None
 
-    fmtstring = _determine_format_string( dates, config['datetime_format'] )
+    fmtstring = _determine_format_string(dates, config['datetime_format'])
 
     ptype = config['type']