Holds a row from a pivot table, which abstractly always has a key, and a bunch of columns with numeric values that represent things like sums or counts or averages
        //@wurfless :^)
        public Dictionary <String, Dictionary <String, Double> > GetSimilarityGraph(PivotTable signature)
        {
            Dictionary <String, Dictionary <String, Double> > outputGraph = new Dictionary <string, Dictionary <string, double> >();

            if (signature.Count < 2)
            {
                return(outputGraph);
            }

            for (int i = 0; i < signature.Count; i++)
            {
                ///tricky... creates an acyclic undirected, non repeating graph
                for (int x = i + 1; x < signature.Count; x++)
                {
                    PivotTableEntry a   = signature[i];
                    PivotTableEntry b   = signature[x];
                    double          sim = GetSparseSimilarity(a, b, true, false).prob;
                    if (outputGraph.ContainsKey(a.RowKey))
                    {
                        outputGraph[a.RowKey].Add(b.RowKey, sim);
                    }
                    else
                    {
                        Dictionary <String, double> newInnerMap = new Dictionary <string, double>();
                        newInnerMap.Add(b.RowKey, sim);
                        outputGraph.Add(a.RowKey, newInnerMap);
                    }
                }
            }


            return(outputGraph);
        }
        public PivotTable GetSparseSimilarites(PivotTableEntry baseVector, PivotTable vectors, bool logarithm, bool onlyBase)
        {
            this.pbarUpdate(vectors.Count, 0, 0);

            PivotTable outMap = new PivotTable();
            int        i      = 0;

            foreach (PivotTableEntry b in vectors)
            {
                PivotTableAnalysisResult similarity = GetSparseSimilarity(baseVector, b, logarithm, onlyBase);
                similarity.Data.Add("cos_sim", similarity.prob);
                Dictionary <String, double> diffData = CalculateDiffs(baseVector, b);
                foreach (String key in diffData.Keys)
                {
                    if (!similarity.Data.ContainsKey(key))
                    {
                        similarity.Data.Add(key, diffData[key]);
                    }
                }
                outMap.Add(similarity);
                this.pbarValueUpdate(i);
                i++;
            }
            return(outMap);
        }
        /// <summary>
        /// Calculates the difference between the values in entry a and b. The resulting distribution is normalized to a value between 0 and 1
        /// </summary>
        /// <param name="a"></param>
        /// <param name="b"></param>
        /// <returns></returns>
        public Dictionary <String, Double> CalculateDiffs(PivotTableEntry a, PivotTableEntry b)
        {
            Dictionary <String, Double> diffs = new Dictionary <String, Double>();
            HashSet <string>            keys  = new HashSet <string>();

            foreach (string k in a.Data.Keys)
            {
                if (k != "OBJECTID")
                {
                    keys.Add(k);
                }
            }
            foreach (string k in b.Data.Keys)
            {
                if (k != "OBJECTID")
                {
                    keys.Add(k);
                }
            }
            foreach (string key in keys)
            {
                if (key == "OBJECTID")
                {
                    continue;
                }
                double x = Double.MinValue;
                double y = Double.MinValue;
                if (a.Data.ContainsKey(key))
                {
                    x = a.Data[key];
                }
                if (b.Data.ContainsKey(key))
                {
                    y = b.Data[key];
                }
                //calc the simple percent diff
                double theDiff = Math.Abs((x - y) / (x + y));
                double percent = 0;
                double av      = (x + y) / 2;
                double dif     = Math.Abs(x - y);
                if (x != 0 && y != 0)
                {
                    percent = Math.Abs((x - y) / (x + y));
                }
                if (percent > 0)
                {
                    diffs.Add(key, Math.Round(percent, 2));
                }
                else
                {
                    diffs.Add(key, 0d);
                }
            }
            return(diffs);
        }
        public PivotTable GenerateAverageVector(PivotTable tableWithMoreThanOneRow)
        {
            if (tableWithMoreThanOneRow.Count < 2)
            {
                throw new Exception("Must Have more than one row");
            }

            Dictionary <String, List <Double> > data = new Dictionary <String, List <Double> >();

            //consolidate all the values for each column of each entry in the pivot table
            foreach (PivotTableEntry entry in tableWithMoreThanOneRow)
            {
                foreach (String key in entry.Data.Keys)
                {
                    if (data.ContainsKey(key))
                    {
                        data[key].Add(entry.Data[key]);
                    }
                    else
                    {
                        List <Double> newList = new List <Double>();
                        newList.Add(entry.Data[key]);
                        data.Add(key, newList);
                    }
                }
            }
            //now average each and produce a new data dictionary
            Dictionary <String, Double> averages = new Dictionary <String, Double>();

            foreach (String key in data.Keys)
            {
                double avg = 0d;
                foreach (Double val in data[key])
                {
                    avg += val;
                }
                avg = avg / data[key].Count;
                averages.Add(key, avg);
            }
            PivotTableEntry newEntry = new PivotTableEntry()
            {
                Data    = averages,
                Context = tableWithMoreThanOneRow[0].Context,
                RowKey  = tableWithMoreThanOneRow[0].RowKey
            };

            PivotTable pt = new PivotTable();

            pt.Add(newEntry);
            return(pt);
        }
 /// <summary>
 /// Calculates the difference between the values in entry a and b. The resulting distribution is normalized to a value between 0 and 1
 /// </summary>
 /// <param name="a"></param>
 /// <param name="b"></param>
 /// <returns></returns>
 public Dictionary<String, Double> CalculateDiffs(PivotTableEntry a, PivotTableEntry b)
 {
     Dictionary<String, Double> diffs = new Dictionary<String, Double>();
       HashSet<string> keys = new HashSet<string>();
       foreach (string k in a.Data.Keys) {
     if (k != "OBJECTID") {
       keys.Add(k);
     }
       }
       foreach (string k in b.Data.Keys) {
     if (k != "OBJECTID") {
       keys.Add(k);
     }
       }
       foreach (string key in keys) {
     if (key == "OBJECTID") {
       continue;
     }
     double x = Double.MinValue;
     double y = Double.MinValue;
     if (a.Data.ContainsKey(key)) { x = a.Data[key]; }
     if (b.Data.ContainsKey(key)) { y = b.Data[key]; }
     //calc the simple percent diff
     double theDiff = Math.Abs((x - y) / (x + y));
     double percent = 0;
     double av = (x + y) / 2;
     double dif = Math.Abs(x - y);
     if (x != 0 && y != 0) {
       percent = Math.Abs((x - y) / (x + y));
     }
     if (percent > 0) {
       diffs.Add(key, Math.Round(percent, 2));
     }
     else {
       diffs.Add(key,0d);
     }
       }
       return diffs;
 }
        public PivotTable FeaturesToPivotTable(
            List<IFeature> layers,
            string rowKeyColName,
            List<string> columnsToIgnore)
        {
            SendAnInt sai = this.UpdatePBar;
            this.pbarChangeDet.Minimum = 0;
            this.pbarChangeDet.Maximum = layers.Count;
            this.pbarChangeDet.Value = 0;

            if (columnsToIgnore == null)
            {
                columnsToIgnore = new List<string>();
            }
            if (!columnsToIgnore.Contains("OBJECTID"))
            {
                columnsToIgnore.Add("OBJECTID");
            }
            var pt = new PivotTable();

            // IFeature feature = featureCursor.NextFeature();
            // loop through the returned features and get the value for the field
            var x = 0;
            foreach (var feature in layers)
            {
                var entry = new PivotTableEntry();
                //do something with each feature(ie update geometry or attribute)
                //  Console.WriteLine("The {0} field contains a value of {1}", nameOfField, feature.get_Value(fieldIndexValue));
                this.pbarChangeDet.Value++;
                sai.Invoke(x);
                x++;
                for (var i = 0; i < feature.Fields.FieldCount; i++)
                {
                    if (this.pbarChangeDet.Value == this.pbarChangeDet.Maximum)
                    {
                        this.pbarChangeDet.Maximum = this.pbarChangeDet.Maximum + 10;
                    }

                    var fname = feature.Fields.get_Field(i).Name;
                    var val = feature.get_Value(i).ToString();

                    if (columnsToIgnore.Contains(fname))
                    {
                        continue;
                    }

                    if (fname.Equals(rowKeyColName))
                    {
                        entry.RowKey = Convert.ToString(val);
                    }
                    else
                    {
                        try
                        {
                            entry.Data.Add(fname, int.Parse(val));
                        }
                        catch
                        {
                        }
                    }
                }
                pt.Add(entry);
            }
            sai.Invoke(Convert.ToInt32(this.pbarChangeDet.Maximum));
            return pt;
        }
        /// <summary>
        /// Returns a PivotTableAnalysisResult with an empty Data dictionary but with a prob
        /// score set to the cosine similarity value of the two input vector spaces.
        /// Look here for more info:  https://upload.wikimedia.org/math/4/e/4/4e45dc7ae582130813e804f793f24ead.png
        ///</summary>
        ///
        /// <param name="a"></param>The base vectors
        /// <param name="b"></param>
        /// <param name="logarithm"></param>
        /// <param name="onlyBase"></param>
        /// <returns></returns>
        public PivotTableAnalysisResult GetSparseSimilarity(PivotTableEntry a, PivotTableEntry b, bool logarithm, bool onlyBase)
        {
            if (a == null || b == null)
            {
                throw new Exception("neither a nor b are allowed to be null");
            }
            PivotTableAnalysisResult prob = new PivotTableAnalysisResult();
            Double           aSoS = 0d, bSoS = 0d, dotProd = 0d;
            HashSet <string> keys = new HashSet <string>();

            foreach (string k in a.Data.Keys)
            {
                if (k != "OBJECTID")
                {
                    keys.Add(k);
                }
            }
            if (!onlyBase)
            {
                foreach (string k in b.Data.Keys)
                {
                    if (k != "OBJECTID")
                    {
                        keys.Add(k);
                    }
                }
            }
            foreach (string key in keys)
            {
                if (key == "OBJECTID")
                {
                    continue;
                }
                double x = 0d;
                double y = 0d;
                if (a.Data.ContainsKey(key))
                {
                    x = a.Data[key];
                }
                if (b.Data.ContainsKey(key))
                {
                    y = b.Data[key];
                }
                if (logarithm)
                {
                    x = Math.Log10(x + 1);
                    y = Math.Log10(y + 1);
                }
                aSoS    += x * x;
                bSoS    += y * y;
                dotProd += x * y;
            }
            if (dotProd == 0)
            {
                return(new PivotTableAnalysisResult()
                {
                    prob = -1d, RowKey = b.RowKey, Context = b.Context
                });
            }
            double div = (Math.Sqrt(aSoS) * Math.Sqrt(bSoS));

            if (div == 0d)
            {
                return(new PivotTableAnalysisResult()
                {
                    prob = -1d, RowKey = b.RowKey, Context = b.Context
                });
            }
            Double similarity = dotProd / div;
            PivotTableAnalysisResult idprob = new PivotTableAnalysisResult()
            {
                prob = similarity, RowKey = b.RowKey, Context = b.Context
            };

            return(idprob);
        }
        /// <summary>
        /// Compares two pivot tables. Do not pass in columns that don't make sense to compare. This method encapsulates a cosine similarity
        /// calculation on geohash cell pairs, and subsequently, each pair also calculates a diff between each col pair as a quasi percentage diff.
        ///
        /// </summary>
        /// <param name="timeA"></param>
        /// <param name="timeB"></param>A PivotTable that is full
        /// <returns></returns>
        public PivotTable DetectChange(PivotTable ptA, PivotTable ptB, string label, bool diffs)
        {
            PivotTable outList = new PivotTable();
            //each dictionary below is a geohash agg layer, key=aGeoHashPrefix,value=anAggVectorOfThatBox
            Dictionary <string, PivotTableEntry> a = new Dictionary <string, PivotTableEntry>();
            Dictionary <string, PivotTableEntry> b = new Dictionary <string, PivotTableEntry>();
            HashSet <string> hashset = new HashSet <string>();

            //union the key sets into hashset variable
            foreach (PivotTableEntry av in ptA)
            {
                a.Add(av.RowKey, av);
                hashset.Add(av.RowKey);
            }
            foreach (PivotTableEntry av in ptB)
            {
                b.Add(av.RowKey, av);
                hashset.Add(av.RowKey);
            }

            this.pbarUpdate.Invoke(hashset.Count, 0, 0);
            //now hashset variable is a unique list of strings
            Dictionary <string, double> empty = new Dictionary <string, double>();

            foreach (String s in hashset)
            {
                empty.Add(s, 0d);
            }
            int x = 0;

            foreach (string geohash in hashset)
            {
                this.pbarValueUpdate.Invoke(x);
                x++;
                PivotTableEntry ava = null;
                PivotTableEntry avb = null;
                if (a.ContainsKey(geohash))
                {
                    ava = a[geohash];
                }
                if (b.ContainsKey(geohash))
                {
                    avb = b[geohash];
                }
                if (ava == null || avb == null)
                {
                    outList.Add(new PivotTableAnalysisResult()
                    {
                        RowKey = geohash, prob = 0d, Data = empty, Label = label
                    });
                }
                else
                {
                    PivotTableAnalysisResult p = GetSparseSimilarity(ava, avb, true, false);
                    p.RowKey = geohash;
                    p.Label  = label;
                    if (diffs)
                    {
                        p.Data = CalculateDiffs(ava, avb);
                    }
                    else
                    {
                        p.Data = new Dictionary <string, double>();
                    }
                    p.Data.Add("cos_sim", p.prob);
                    p.Data.Add("percent_change", Math.Abs(p.prob - 1) * 100);
                    outList.Add(p);
                }
            }
            return(outList);
        }
        public PivotTable FeatureLayerToPivotTable(
            IFeatureLayer layer,
            string rowKeyColName,
            List<string> columnsToIgnore)
        {
            SendAnInt sai = this.UpdatePBar;
            this.analysisProgressBar.Minimum = 0;
            this.analysisProgressBar.Maximum = layer.FeatureClass.FeatureCount(null);
            this.analysisProgressBar.Value = 0;

            if (columnsToIgnore == null)
            {
                columnsToIgnore = new List<string>();
            }
            if (!columnsToIgnore.Contains("OBJECTID"))
            {
                columnsToIgnore.Add("OBJECTID");
            }
            var pt = new PivotTable();
            if (PivotTableCache.Cache.ContainsKey(layer.Name))
            {
                pt = PivotTableCache.Cache[layer.Name];
                return pt;
            }

            var featureCursor = layer.FeatureClass.Search(null, false);
            var feature = featureCursor.NextFeature();
            // loop through the returned features and get the value for the field
            var x = 0;
            while (feature != null)
            {
                var entry = new PivotTableEntry();
                //do something with each feature(ie update geometry or attribute)
                this.analysisProgressBar.Value++;
                sai.Invoke(x);
                x++;
                for (var i = 0; i < feature.Fields.FieldCount; i++)
                {
                    if (this.analysisProgressBar.Value == this.analysisProgressBar.Maximum)
                    {
                        this.analysisProgressBar.Maximum = this.analysisProgressBar.Maximum + 10;
                    }

                    var f = feature.Fields.get_Field(i).Name;
                    var val = feature.get_Value(i).ToString();

                    if (columnsToIgnore.Contains(f))
                    {
                        continue;
                    }

                    if (f.Equals(rowKeyColName))
                    {
                        entry.RowKey = Convert.ToString(val);
                    }
                    else
                    {
                        try
                        {
                            entry.Data.Add(f, int.Parse(val));
                        }
                        catch
                        {
                        }
                    }
                }
                pt.Add(entry);
                feature = featureCursor.NextFeature();
            }

            sai.Invoke(Convert.ToInt32(this.analysisProgressBar.Maximum));
            //add to the cache
            if (!PivotTableCache.Cache.ContainsKey(layer.Name))
            {
                PivotTableCache.Cache.Add(layer.Name, pt);
            }
            return pt;
        }
 /// <summary>
 /// Returns a PivotTableAnalysisResult with an empty Data dictionary but with a prob 
 /// score set to the cosine similarity value of the two input vector spaces.
 /// Look here for more info:  https://upload.wikimedia.org/math/4/e/4/4e45dc7ae582130813e804f793f24ead.png
 ///</summary>
 ///
 /// <param name="a"></param>The base vectors
 /// <param name="b"></param>
 /// <param name="logarithm"></param>
 /// <param name="onlyBase"></param>
 /// <returns></returns>
 public PivotTableAnalysisResult GetSparseSimilarity(PivotTableEntry a, PivotTableEntry b, bool logarithm, bool onlyBase)
 {
     if (a == null || b == null) {
     throw new Exception("neither a nor b are allowed to be null");
       }
       PivotTableAnalysisResult prob = new PivotTableAnalysisResult();
       Double aSoS = 0d, bSoS = 0d, dotProd = 0d;
       HashSet<string> keys = new HashSet<string>();
       foreach (string k in a.Data.Keys) {
     if (k != "OBJECTID") {
       keys.Add(k);
     }
       }
       if (!onlyBase) {
     foreach (string k in b.Data.Keys) {
       if (k != "OBJECTID") {
     keys.Add(k);
       }
     }
       }
       foreach (string key in keys) {
     if (key == "OBJECTID") {
       continue;
     }
     double x = 0d;
     double y = 0d;
     if (a.Data.ContainsKey(key)) { x = a.Data[key]; }
     if (b.Data.ContainsKey(key)) { y = b.Data[key]; }
     if (logarithm) {
       x = Math.Log10(x + 1);
       y = Math.Log10(y + 1);
     }
     aSoS += x * x;
     bSoS += y * y;
     dotProd += x * y;
       }
       if (dotProd == 0) {
     return new PivotTableAnalysisResult() { prob = -1d, RowKey = b.RowKey, Context = b.Context };
       }
       double div = (Math.Sqrt(aSoS) * Math.Sqrt(bSoS));
       if (div == 0d) {
     return new PivotTableAnalysisResult() { prob = -1d, RowKey = b.RowKey, Context = b.Context };
       }
       Double similarity = dotProd / div;
       PivotTableAnalysisResult idprob = new PivotTableAnalysisResult() { prob = similarity, RowKey = b.RowKey, Context = b.Context };
       return idprob;
 }
        public PivotTable GetSparseSimilarites(PivotTableEntry baseVector, PivotTable vectors, bool logarithm, bool onlyBase)
        {
            this.pbarUpdate(vectors.Count, 0, 0);

              PivotTable outMap = new PivotTable();
              int i = 0;
              foreach (PivotTableEntry b in vectors) {
            PivotTableAnalysisResult similarity = GetSparseSimilarity(baseVector, b, logarithm, onlyBase);
            similarity.Data.Add("cos_sim", similarity.prob);
            Dictionary<String, double> diffData = CalculateDiffs(baseVector, b);
            foreach (String key in diffData.Keys) {
              if (!similarity.Data.ContainsKey(key)) {
            similarity.Data.Add(key, diffData[key]);
              }
            }
            outMap.Add(similarity);
            this.pbarValueUpdate(i);
            i++;
              }
              return outMap;
        }
        public PivotTable GenerateAverageVector(PivotTable tableWithMoreThanOneRow)
        {
            if (tableWithMoreThanOneRow.Count < 2) {
            throw new Exception("Must Have more than one row");
              }

              Dictionary<String, List<Double>> data = new Dictionary<String, List<Double>>();
              //consolidate all the values for each column of each entry in the pivot table
              foreach (PivotTableEntry entry in tableWithMoreThanOneRow) {
            foreach (String key in entry.Data.Keys) {
              if (data.ContainsKey(key)) {
            data[key].Add(entry.Data[key]);
              }
              else {
            List<Double> newList = new List<Double>();
            newList.Add(entry.Data[key]);
            data.Add(key,newList);
              }
            }
              }
              //now average each and produce a new data dictionary
              Dictionary<String, Double> averages = new Dictionary<String, Double>();
              foreach (String key in data.Keys) {
            double avg = 0d;
            foreach (Double val in data[key]) {
              avg += val;
            }
            avg = avg / data[key].Count;
            averages.Add(key, avg);
              }
              PivotTableEntry newEntry = new PivotTableEntry() {
            Data = averages,
            Context = tableWithMoreThanOneRow[0].Context,
            RowKey = tableWithMoreThanOneRow[0].RowKey
              };

              PivotTable pt = new PivotTable();
              pt.Add(newEntry);
              return pt;
        }