Support discontinuities with NaN

Author: NathanBaulch

AsciiChart.Sharp.Tests/Tests.cs

@@ -187,6 +187,31 @@ public void TestPlot(double[] series, Options opts, string expected)
  38.46 ┤                                                     ││ │││
  37.46 ┤                                                     ╰╯ │││
  36.45 ┤                                                        ╰╯╰ "
+            },
+            new object[] { new[] { 1, 1, double.NaN, 1, 1 }, null, @" 1.00 ┼─╴╶─ " },
+            new object[] { new[] { double.NaN, 1 }, null, @" 1.00 ┤╶ " },
+            new object[]
+            {
+                new[] { 0, 0, 1, 1, double.NaN, double.NaN, 3, 3, 4 }, null, @"
+ 4.00 ┤       ╭
+ 3.00 ┤     ╶─╯
+ 2.00 ┤
+ 1.00 ┤ ╭─╴
+ 0.00 ┼─╯       "
+            },
+            new object[]
+            {
+                new[] { 0.1, 0.2, 0.3, double.NaN, 0.5, 0.6, 0.7, double.NaN, double.NaN, 0.9, 1 }, new Options { Height = 9 }, @"
+ 1.00 ┤         ╭
+ 0.90 ┤        ╶╯
+ 0.80 ┤
+ 0.70 ┤     ╭╴
+ 0.60 ┤    ╭╯
+ 0.50 ┤   ╶╯
+ 0.40 ┤
+ 0.30 ┤ ╭╴
+ 0.20 ┤╭╯
+ 0.10 ┼╯          "
             }
         };
     }

AsciiChart.Sharp/AsciiChart.cs

@@ -19,7 +19,7 @@ public static string Plot(IEnumerable<double> series, Options options = null)
             options = options ?? new Options();
 
             var seriesList = series.ToList();
-            var min = seriesList.Min();
+            var min = seriesList.Where(v => !double.IsNaN(v)).Min();
             var max = seriesList.Max();
 
             var range = Math.Abs(max - min);
@@ -37,13 +37,28 @@ public static string Plot(IEnumerable<double> series, Options options = null)
             ApplyYAxisLabels(resultArray, yAxisLabels, columnIndexOfFirstDataPoint);
 
             var rowIndex0 = Math.Round(seriesList[0] * ratio, MidpointRounding.AwayFromZero) - min2;
-            resultArray[(int) (rows - rowIndex0)][columnIndexOfFirstDataPoint - 1] = "┼";
+            if (!double.IsNaN(rowIndex0))
+            {
+                resultArray[(int) (rows - rowIndex0)][columnIndexOfFirstDataPoint - 1] = "┼";
+            }
 
             for (var x = 0; x < seriesList.Count - 1; x++)
             {
                 var rowIndex1 = Math.Round(seriesList[x + 1] * ratio, MidpointRounding.AwayFromZero) - min2;
+                if (double.IsNaN(rowIndex0) && double.IsNaN(rowIndex1))
+                {
+                    continue;
+                }
 
-                if (rowIndex0 == rowIndex1)
+                if (double.IsNaN(rowIndex0))
+                {
+                    resultArray[(int) (rows - rowIndex1)][x + columnIndexOfFirstDataPoint] = "╶";
+                }
+                else if (double.IsNaN(rowIndex1))
+                {
+                    resultArray[(int) (rows - rowIndex0)][x + columnIndexOfFirstDataPoint] = "╴";
+                }
+                else if (rowIndex0 == rowIndex1)
                 {
                     resultArray[(int) (rows - rowIndex0)][x + columnIndexOfFirstDataPoint] = "─";
                 }
@@ -57,9 +72,9 @@ public static string Plot(IEnumerable<double> series, Options options = null)
                     {
                         resultArray[(int) (rows - y)][x + columnIndexOfFirstDataPoint] = "│";
                     }
-
-                    rowIndex0 = rowIndex1;
                 }
+
+                rowIndex0 = rowIndex1;
             }
 
             return ToString(resultArray);