add renko_params arg and _renko_params_validator

Author: coffincw

src/mplfinance/_arg_validators.py

@@ -56,6 +56,48 @@ def _mav_validator(mav_value):
             return False
     return True
 
+def _renko_params_validator(params_dict):
+    ''' 
+    Ranko params may not have > 3 parameters, their values may be:
+    type: must be either 'pmove' or 'pclose'
+    brick_size: must be either an int/float greater than 0 or 'atr'
+    atr_length: must only exist if brick_size is 'atr', must be an int greater than 0
+    '''
+    if len(params_dict) > 3:
+        return False
+
+    # Validate type
+    if 'type' in params_dict:
+        if params_dict['type'] not in ['pmove', 'pclose']:
+            return False
+    else:
+        params_dict['type'] = 'pmove' # Set default value of type to price movement
+    
+    # Validate brick_size and atr_length
+    if 'brick_size' in params_dict:
+        brick_size = params_dict['brick_size']
+        if not isinstance(brick_size, int) and not isinstance(brick_size, float):
+            if brick_size != 'atr':
+                return False
+            else:
+                if 'atr_length' not in params_dict:
+                    params_dict['atr_length'] = 14 # Set default value of atr_length to 14
+                else:
+                    if not isinstance(params_dict['atr_length'], int) or params_dict['atr_length'] < 1:
+                        return False
+        else: 
+            if brick_size < 0 or 'atr_length' in params_dict: 
+                return False
+    else:
+        params_dict['brick_size'] = 'atr'
+        params_dict['atr_length'] = 14
+        
+    return True
+                
+        
+
+
+
 def _bypass_kwarg_validation(value):
     ''' For some kwargs, we either don't know enough, or
         the validation is too complex to make it worth while,

src/mplfinance/plotting.py

@@ -14,12 +14,13 @@
 
 from mplfinance._utils import _construct_ohlc_collections
 from mplfinance._utils import _construct_candlestick_collections
+
 from mplfinance._utils import _updown_colors
 from mplfinance._utils import IntegerIndexDateTimeFormatter
 
 from mplfinance import _styles
 
-from mplfinance._arg_validators import _check_and_prepare_data, _mav_validator
+from mplfinance._arg_validators import _check_and_prepare_data, _mav_validator, _renko_params_validator
 from mplfinance._arg_validators import _process_kwargs, _validate_vkwargs_dict
 from mplfinance._arg_validators import _kwarg_not_implemented, _bypass_kwarg_validation
 
@@ -72,6 +73,9 @@ def _valid_plot_kwargs():
 
         'mav'         : { 'Default'     : None,
                           'Validator'   : _mav_validator },
+        
+        'renko_params': { 'Default'     : dict(type='pmove', brick_size='atr', atr_length=14),
+                          'Validator'   : _renko_params_validator },
 
         'study'       : { 'Default'     : None,
                          #'Validator'   : lambda value: isinstance(value,dict) }, #{'studyname': {study parms}} example: {'TE':{'mav':20,'upper':2,'lower':2}}