diff --git a/rowers/dataroutines.py b/rowers/dataroutines.py
index 3bcd683d..822230d3 100644
--- a/rowers/dataroutines.py
+++ b/rowers/dataroutines.py
@@ -31,6 +31,7 @@ from zipfile import BadZipFile
 import zipfile
 import os
 from rowers.models import strokedatafields
+import polars as pl
 
 from rowingdata import (
     KinoMapParser,
@@ -400,12 +401,16 @@ def clean_df_stats(datadf, workstrokesonly=True, ignorehr=True,
     try:
         _ = datadf['workoutid'].unique()
     except KeyError:
-        datadf['workoutid'] = 0
+        try:
+            datadf['workoutid'] = 0
+        except TypeError:
+            datadf = datadf.with_columns(pl.lit(0).alias("workoutid"))
 
     before = {}
-    for workoutid in datadf['workoutid'].unique():
+    ids = datadf['workoutid'].unique()
+    for workoutid in ids:
         before[workoutid] = len(datadf[datadf['workoutid'] == workoutid])
-
+        
     data_orig = datadf.copy()
 
     # bring metrics which have negative values to positive domain
@@ -654,6 +659,258 @@ def clean_df_stats(datadf, workstrokesonly=True, ignorehr=True,
 
     return datadf
 
+def replace_zeros_with_nan(x):
+    return np.nan if x == 0 else x
+
+def clean_df_stats_pl(datadf, workstrokesonly=True, ignorehr=True,
+                   ignoreadvanced=False, for_chart=False):
+    # clean data remove zeros and negative values
+
+    try:
+        _ = datadf['workoutid'].unique()
+    except KeyError:
+        try:
+            datadf['workoutid'] = 0
+        except TypeError:
+            datadf = datadf.with_columns(pl.lit(0).alias("workoutid"))
+
+    before = {}
+    ids = list(datadf['workoutid'].unique())
+    for workoutid in ids:
+        before[workoutid] = len(datadf.filter(pl.col("workoutid")==workoutid))
+        
+    data_orig = datadf.clone()
+
+    # bring metrics which have negative values to positive domain
+    if len(datadf) == 0:
+        return datadf
+    try:
+        datadf = datadf.with_columns((-pl.col('catch')).alias('catch'))
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.with_columns((pl.col('peakforceangle')+1000).alias('peakforceangle'))
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.with_columns((pl.col('hr')+10).alias('hr'))
+    except (KeyError, TypeError):
+        pass
+
+    # protect 0 spm values from being nulled
+    try:
+        datadf = datadf.with_columns((pl.col('spm')+1.0).alias('spm'))
+    except (KeyError, TypeError):
+        pass
+
+    # protect 0 workoutstate values from being nulled
+    try:
+        datadf = datadf.with_columns((pl.col('workoutstate')+1).alias('workoutstate'))
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.select(pl.all().clip(lower_bound=0))
+        #        datadf = datadf.clip(lower=0)
+    except TypeError:
+        pass
+
+    # protect advanced metrics columns
+    advancedcols = [
+        'rhythm',
+        'power',
+        'drivelength',
+        'forceratio',
+        'drivespeed',
+        'driveenergy',
+        'catch',
+        'finish',
+        'averageforce',
+        'peakforce',
+        'slip',
+        'wash',
+        'peakforceangle',
+        'effectiveangle',
+    ]
+
+    for col in datadf.columns:
+        datadf = datadf.with_columns(
+            pl.when(datadf[col] == 0).then(pl.lit(np.nan)).otherwise(datadf[col]),
+            name=col
+            )
+
+    #    datadf = datadf.map_partitions(lambda df:df.replace(to_replace=0,value=np.nan))
+
+    # bring spm back to real values
+    try:
+        datadf = datadf.with_columns((pl.col('spm')-1.0).alias('spm'))
+    except (TypeError, KeyError):
+        pass
+
+    # bring workoutstate back to real values
+    try:
+        datadf = datadf.with_columns((pl.col('workoutstate')-1).alias('workoutstate'))
+    except (TypeError, KeyError):
+        pass
+
+    # return from positive domain to negative
+    try:
+        datadf = datadf.with_columns((-pl.col('catch')).alias('catch'))
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.with_columns((pl.col('peakforceangle')-1000).alias('peakforceangle'))
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.with_columns((pl.col('hr')+10).alias('hr'))
+    except (KeyError, TypeError):
+        pass
+
+    # clean data for useful ranges per column
+    if not ignorehr:
+        try:
+            datadf = datadf.filter(pl.col("hr")>=30)
+        except (KeyError, TypeError):  # pragma: no cover
+            pass
+
+    try:
+        datadf = datadf.filter(pl.col("spm") >=0)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("efficiency")<=200)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("spm")>=10)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("pace")<=300*1000.)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("efficiency")>=0)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("pace")>=60*1000)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("power")<=5000)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("spm")<=120)
+    except (KeyError, TypeError):
+        pass
+
+    try:
+        datadf = datadf.filter(pl.col("wash")>=1)
+    except (KeyError, TypeError):
+        pass
+
+    # try to guess ignoreadvanced
+    if not ignoreadvanced:
+        for metric in advancedcols:
+            try:
+                sum = datadf[metric].std()
+                if sum == 0 or np.isnan(sum):
+                    ignoreadvanced = True
+            except KeyError:
+                pass
+
+    if not ignoreadvanced:
+        try:
+            datadf = datadf.filter(pl.col("rhythm")>=0)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("rhythm")<=70)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("power")>=20)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("drivelength")>=0.5)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("forceratio")>=0.2)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("forceratio")<=1.0)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("drivespeed")>=0.5)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("drivespeed")<=4)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("driveenergy")<=2000)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("driveenergy")>=100)
+        except (KeyError, TypeError):
+            pass
+
+        try:
+            datadf = datadf.filter(pl.col("catch")<=-30)
+        except (KeyError, TypeError):
+            pass
+
+    # workoutstateswork = [1, 4, 5, 8, 9, 6, 7]
+    workoutstatesrest = [3]
+    # workoutstatetransition = [0, 2, 10, 11, 12, 13]
+
+    if workstrokesonly == 'True' or workstrokesonly is True:
+        try:
+            datadf = datadf.filter(~pl.col("workoutstate").is_in(workoutstatesrest))
+        except:
+            pass
+
+    after = {}
+
+    if for_chart:
+        return datadf
+    for workoutid in data_orig['workoutid'].unique():
+        after[workoutid] = len(datadf.filter(pl.col("workoutid")==workoutid))
+        ratio = float(after[workoutid])/float(before[workoutid])
+        if ratio < 0.01 or after[workoutid] < 2:
+            return data_orig
+
+    return datadf
+
 
 def getpartofday(row, r):
     workoutstartdatetime = row.rowdatetime
@@ -863,12 +1120,6 @@ def get_workoutsummaries(userid, startdate):  # pragma: no cover
     return df
 
 
-
-
-
-
-
-
 def checkduplicates(r, workoutdate, workoutstartdatetime, workoutenddatetime):
     duplicate = False
     ws = Workout.objects.filter(user=r, date=workoutdate, duplicate=False).exclude(
@@ -1244,6 +1495,84 @@ def getrowdata_db(id=0, doclean=False, convertnewtons=True,
 
 # Fetch a subset of the data from the DB
 
+def getsmallrowdata_pl(columns, ids=[], doclean=True, workstrokesonly=True, compute=True,
+                       debug=False, for_chart=False):
+    if ids:
+        csvfilenames = [
+            'media/strokedata_{id}.parquet.gz'.format(id=id) for id in ids]
+    else:
+        return pl.DataFrame()
+
+    data = []
+    columns = [c for c in columns if c != 'None'] + ['distance', 'spm', 'workoutid']
+    columns = list(set(columns))
+
+    df = pl.DataFrame()
+    if len(ids) > 1:
+        for id, f in zip(ids, csvfilenames):
+            try:
+                df = pl.read_parquet(f, columns=columns)
+                data.append(df)
+            except (IsADirectoryError, FileNotFoundError, OSError, ArrowInvalid, IndexError):  # pragma: no cover
+                rowdata, row = getrowdata(id=id)
+                shutil.rmtree(f)
+                if rowdata and len(rowdata.df):
+                    _ = dataprep(rowdata.df, id=id,
+                                 bands=True, otwpower=True, barchart=True,
+                                 polars=True)
+                    try:
+                        df = pl.read_parquet(f, columns=columns)
+                        data.append(df)
+                    except (OSError, ArrowInvalid, IndexError):
+                        pass
+        try:
+            df = pl.concat(data, rechunk=True)
+        except ValueError:  # pragma: no cover
+            return pl.DataFrame()
+
+    else:
+        try:
+            df = pl.read_parquet(csvfilenames[0], columns=columns)
+            rowdata, row = getrowdata(id=ids[0])
+        except (OSError, IndexError, ArrowInvalid):
+            rowdata, row = getrowdata(id=ids[0])
+            if rowdata and len(rowdata.df):  # pragma: no cover
+                data = dataprep(
+                    rowdata.df, id=ids[0], bands=True, otwpower=True, barchart=True)
+                try:
+                    df = pd.read_parquet(csvfilenames[0], columns=columns)
+                except:
+                    df = pd.DataFrame
+            else:
+                df = pd.DataFrame()
+        except:
+            rowdata, row = getrowdata(id=ids[0])
+            if rowdata and len(rowdata.df):  # pragma: no cover
+                data = dataprep(
+                    rowdata.df, id=ids[0], bands=True, otwpower=True, barchart=True)
+                try:
+                    df = pd.read_parquet(csvfilenames[0], columns=columns)
+                except:
+                    df = pd.DataFrame()
+            else:
+                df = pd.DataFrame()
+
+    if compute and len(df):
+        data = df.clone()
+        if doclean:
+            data = clean_df_stats_pl(data, ignorehr=True,
+                                     workstrokesonly=workstrokesonly,
+                                     for_chart=for_chart)
+
+        data = data.drop_nulls()
+
+        return data
+
+
+    return df
+
+    
+    
 
 def getsmallrowdata_db(columns, ids=[], doclean=True, workstrokesonly=True, compute=True,
                        debug=False, for_chart=False):
@@ -1593,7 +1922,7 @@ def add_efficiency(id=0):  # pragma: no cover
 
 
 def dataprep(rowdatadf, id=0, bands=True, barchart=True, otwpower=True,
-             empower=True, inboard=0.88, forceunit='lbs', debug=False):
+             empower=True, inboard=0.88, forceunit='lbs', debug=False, polars=True):
 
     if rowdatadf.empty:
         return 0
@@ -1873,11 +2202,15 @@ def dataprep(rowdatadf, id=0, bands=True, barchart=True, otwpower=True,
 
         filename = 'media/strokedata_{id}.parquet.gz'.format(id=id)
         df = dd.from_pandas(data, npartitions=1)
-        try:
-            df.to_parquet(filename, engine='fastparquet', compression='GZIP')
-        except FileNotFoundError:
-            df2 = dd.from_pandas(df, npartitions=1)
-            df2.to_parquet(filename, engine='fastparquet', compression='GZIP')
+        if polars:
+            pldf = pl.from_pandas(data)
+            pldf.write_parquet(filename, compression='gzip')
+        else:
+            try:
+                df.to_parquet(filename, engine='fastparquet', compression='gzip')
+            except FileNotFoundError:
+                df2 = dd.from_pandas(df, npartitions=1)
+                df2.to_parquet(filename, engine='fastparquet', compression='gzip')
 
     return data
 
diff --git a/rowers/interactiveplots.py b/rowers/interactiveplots.py
index 4276704f..0178d52f 100644
--- a/rowers/interactiveplots.py
+++ b/rowers/interactiveplots.py
@@ -18,8 +18,10 @@ import rowers.metrics as metrics
 import rowers.dataprep as dataprep
 from rowers.dataprep import rdata
 import rowers.utils as utils
+import polars as pl
 
 from rowers.rower_rules import ispromember
+from polars.exceptions import ColumnNotFoundError
 
 from scipy.interpolate import griddata
 from scipy.signal import savgol_filter
@@ -2306,29 +2308,30 @@ def interactive_cum_flex_chart2(theworkouts, promember=0,
 
     columns = [name for name, d in metrics.rowingmetrics]
     columns_basic = [name for name, d in metrics.rowingmetrics if d['group'] == 'basic']
-    columns = columns + ['spm', 'driveenergy', 'distance']
-    columns_basic = columns_basic + ['spm', 'driveenergy', 'distance']
+    columns = columns + ['spm', 'driveenergy', 'distance' ,'workoutstate']
+    columns_basic = columns_basic + ['spm', 'driveenergy', 'distance', 'workoutstate']
 
     datadf = pd.DataFrame()
     if promember:
-        datadf = dataprep.getsmallrowdata_db(columns, ids=ids, doclean=True,
+        datadf = dataprep.getsmallrowdata_pl(columns, ids=ids, doclean=True,
                                              workstrokesonly=workstrokesonly, for_chart=True)
     else:
-        datadf = dataprep.getsmallrowdata_db(columns_basic, ids=ids, doclean=True,
+        datadf = dataprep.getsmallrowdata_pl(columns_basic, ids=ids, doclean=True,
                                              workstrokesonly=workstrokesonly, for_chart=True)
 
     try:
         _ = datadf[yparam2]
-    except KeyError:  # pragma: no cover
+    except (KeyError, ColumnNotFoundError):  # pragma: no cover
         yparam2 = 'None'
 
     try:
         _ = datadf[yparam1]
-    except KeyError:
+    except (KeyError, ColumnNotFoundError):
         yparam1 = 'None'
 
-    datadf.dropna(axis=1, how='all', inplace=True)
-    datadf.dropna(axis=0, how='any', inplace=True)
+    datadf.drop_nulls()
+    #datadf.dropna(axis=1, how='all', inplace=True)
+    #datadf.dropna(axis=0, how='any', inplace=True)
 
     # test if we have drive energy
     try:  # pragma: no cover
@@ -2347,42 +2350,43 @@ def interactive_cum_flex_chart2(theworkouts, promember=0,
         yparamname2 = axlabels[yparam2]
 
     # check if dataframe not empty
-    if datadf.empty:  # pragma: no cover
+    if datadf.is_empty():  # pragma: no cover
         return ['', '<p>No non-zero data in selection</p>', '', '']
 
     try:
-        datadf['x1'] = datadf.loc[:, xparam]
+        datadf = datadf.with_columns(pl.col(xparam).alias("x1"))
     except KeyError:  # pragma: no cover
         try:
-            datadf['x1'] = datadf['distance']
+            datadf = datadf.with_columns(pl.col("distance").alias("x1"))
         except KeyError:
             try:
-                datadf['x1'] = datadf['time']
+                datadf = datadf.with_columns(pl.col('time').alias("x1"))
             except KeyError:  # pragma: no cover
                 return ['', '<p>No non-zero data in selection</p>', '', '']
 
     try:
-        datadf['y1'] = datadf.loc[:, yparam1]
+        datadf = datadf.with_columns(pl.col(yparam1).alias("y1"))
     except KeyError:
         try:
-            datadf['y1'] = datadf['pace']
+            datadf = datadf.with_columns(pl.col('pace').alias("y1"))
         except KeyError:  # pragma: no cover
             return ['', '<p>No non-zero data in selection</p>', '', '']
     if yparam2 != 'None':
         try:
-            datadf['y2'] = datadf.loc[:, yparam2]
+            datadf = datadf.with_columns(pl.col(yparam2).alias("y2"))
         except KeyError:  # pragma: no cover
-            datadf['y2'] = datadf['y1']
+            datadf = datadf.with_columns(pl.col("y1").alias("y2"))
     else:  # pragma: no cover
-        datadf['y2'] = datadf['y1']
+        datadf = datadf.with_columns(pl.col("y1").alias("y2"))
 
 
-    datadf['xname'] = axlabels[xparam]
-    datadf['yname1'] = axlabels[yparam1]
+    datadf = datadf.with_columns(xname = pl.lit(axlabels[xparam]))
+    datadf = datadf.with_columns(yname1 = pl.lit(axlabels[yparam1]))
+
     if yparam2 != 'None':
-        datadf['yname2'] = axlabels[yparam2]
+        datadf = datadf.with_columns(yname2 = pl.lit(axlabels[yparam2]))
     else:  # pragma: no cover
-        datadf['yname2'] = axlabels[yparam1]
+        datadf = datadf.with_columns(yname2 = pl.lit(axlabels[yparam1]))
 
     def func(x, a, b):
         return a*x+b
@@ -2392,11 +2396,12 @@ def interactive_cum_flex_chart2(theworkouts, promember=0,
     try:
         popt, pcov = optimize.curve_fit(func, x1, y1)
         ytrend = func(x1, popt[0], popt[1])
-        datadf['ytrend'] = ytrend
+        datadf= datadf.with_columns(ytrend = ytrend)
     except TypeError:
-        datadf['ytrend'] = y1
+        datadf = datadf.with_columns(ytrend = y1)
 
-    data_dict = datadf.to_dict("records")
+
+    data_dict = datadf.to_dicts()
 
     metrics_list = [{'name': name, 'rowingmetrics':d } for name, d in metrics.rowingmetrics]
     
diff --git a/rowers/views/analysisviews.py b/rowers/views/analysisviews.py
index 86e353ca..4ff7d4ca 100644
--- a/rowers/views/analysisviews.py
+++ b/rowers/views/analysisviews.py
@@ -296,7 +296,10 @@ def analysis_new(request,
             df = cpdata(tw, options)
         options['savedata'] = False
         request.session['options'] = options
-        response = HttpResponse(df.to_csv())
+        try:
+            response = HttpResponse(df.to_csv())
+        except AttributeError:
+            response = HttpResponse(df.write_csv())
         code = str(uuid4())
         filename = code+'.csv'
         chartform.fields['savedata'].initial = False
@@ -568,7 +571,7 @@ def flexalldata(workouts, options):
         workstrokesonly = not includereststrokes
         columns = [xparam, yparam1, yparam2, 'spm', 'driveenergy', 'distance']
         ids = [int(w.id) for w in workouts]
-        df = dataprep.getsmallrowdata_db(columns, ids=ids,
+        df = dataprep.getsmallrowdata_pl(columns, ids=ids,
                                          workstrokesonly=workstrokesonly,
                                          doclean=True,
                                          )