diff --git a/lib/youplot/backends/unicode_plot_backend.rb b/lib/youplot/backends/unicode_plot_backend.rb
index 50b47cf..0740c99 100644
--- a/lib/youplot/backends/unicode_plot_backend.rb
+++ b/lib/youplot/backends/unicode_plot_backend.rb
@@ -90,6 +90,7 @@ module YouPlot
           params.name   ||= headers[1]
           params.xlabel ||= headers[0]
         end
+        params.xlim ||= series[0].flatten.minmax # why need?
         params.ylim ||= series[1..-1].flatten.minmax # why need?
         plot = UnicodePlot.public_send(method1, series[0], series[1], **params.to_hc)
         2.upto(series.size - 1) do |i|
@@ -103,13 +104,14 @@ module YouPlot
         series = data.series
         method2 = get_method2(method1)
         series.map! { |s| s.map(&:to_f) }
-        series = series.each_slice(2).to_a
+        series2 = series.each_slice(2).to_a
+        series = nil
         params.name ||= headers[0] if headers
-        params.xlim = series.map(&:first).flatten.minmax # why need?
-        params.ylim = series.map(&:last).flatten.minmax  # why need?
+        params.xlim ||= series2.map(&:first).flatten.minmax # why need?
+        params.ylim ||= series2.map(&:last).flatten.minmax # why need?
         x1, y1 = series.shift
         plot = UnicodePlot.public_send(method1, x1, y1, **params.to_hc)
-        series.each_with_index do |(xi, yi), i|
+        series2.each_with_index do |(xi, yi), i|
           UnicodePlot.public_send(method2, plot, xi, yi, name: headers&.[]((i + 1) * 2))
         end
         plot
diff --git a/test/fixtures/iris-density.txt b/test/fixtures/iris-density.txt
index 96ed69f..8e83768 100644
--- a/test/fixtures/iris-density.txt
+++ b/test/fixtures/iris-density.txt
@@ -1,20 +1,20 @@
                      IRIS-DENSITY
        ┌────────────────────────────────────────┐             
-   6.9 │                                        │ sepal_width 
+   6.9 │                                     ░  │ sepal_width 
        │                                        │ petal_length
-       │                                        │ petal_width 
-       │                                        │ species     
-       │                    ░                   │             
-       │                                        │             
+       │                          ░             │ petal_width 
+       │                ░      ░░               │ species     
+       │                   ░  ░                 │             
        │               ░                        │             
-       │          ░                             │             
-       │       ░            ░   ░░ ░            │             
-       │               ░  ░    ░                │             
+       │        ░   ░░  ░                       │             
+       │       ▒░             ░                 │             
+       │ ░   ░░       ░░ ░ ░   ░░ ░░░           │             
+       │             ░  ░     ░   ░             │             
+       │                       ░░   ░        ░  │             
+       │   ░ ░░░▒ ░ ░    ░░░  ░   ░             │             
+       │       ░     ░░░░                       │             
        │                                        │             
-       │       ░ ░▒ ░ ░     ░  ░                │             
-       │          ░    ░ ░                      │             
-       │                                        │             
-     0 │    ░░ ▒ ░█ ░ ░▒ ░░ ░  ░░░ ░            │             
+     0 │ ░ ▒░▒▒██ ▒ ▓▒░▒▒░░░ ░▒▒░ ▒░░   ░    ░  │             
        └────────────────────────────────────────┘             
-       4                                        8
+       4.3                                    7.9
                      sepal_length
diff --git a/test/fixtures/iris-lineplots.txt b/test/fixtures/iris-lineplots.txt
index 2400ed6..0a8f594 100644
--- a/test/fixtures/iris-lineplots.txt
+++ b/test/fixtures/iris-lineplots.txt
@@ -1,20 +1,20 @@
                     IRIS-LINEPLOTS
        ┌────────────────────────────────────────┐             
-   6.9 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣤⣲⠭⠃⠀⠀│ sepal_width 
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⠀⠀⢀⣀⣠⣤⣶⣿⣿⣯⣴⣒⠖⠉⠁│ petal_length
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣤⢮⣤⣤⣶⣿⣿⣿⠿⠛⠛⠋⠉⠀⠀⠀⠀⠀⠀│ petal_width 
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣤⣴⣷⣿⣿⣿⣿⣿⣿⣟⣟⡂⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ species     
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⠤⠔⠒⢙⡻⠝⢋⡽⢝⣳⣾⣫⣥⣒⣪⣵⣖⣂⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠉⠁⠀⠀⢀⣉⣟⣻⣿⣻⣿⣿⣿⠿⣿⣿⠿⠟⡢⠒⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣤⣿⣷⣾⣿⡿⣿⡯⠿⠛⠋⠉⠀⣀⠔⠉⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣄⣀⠄│             
-       │⠀⠀⠀⠀⢀⣨⣽⣿⣿⣿⣿⣿⣿⣿⣵⣚⣉⣃⣀⣠⣤⣤⣔⣮⣤⣄⣀⣠⣤⣔⣲⣾⡳⠮⠛⠋⢉⡗⠁⠀│             
-       │⠀⠀⠐⠒⡿⠿⠟⡻⠛⠛⠛⠚⠉⠀⠲⣶⣿⣷⣾⣷⣿⣿⣷⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣶⣶⣷⡇⠀⠀│             
-       │⠀⠀⠀⠀⢱⡠⠊⠀⠀⣤⣤⣶⣿⣿⠿⣿⣿⣿⣿⣿⣟⣿⣿⣟⣟⣉⣉⣝⣛⣫⣭⣥⣤⣤⣔⣒⣒⡃⠀⠀│             
-       │⠀⠀⠀⠀⠀⠁⠀⢀⡀⠀⢯⠒⠉⡠⠔⠡⠤⠮⣤⣴⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣿⣶⣶⣶⣶⣿⣿⠥⠤⠄│             
-       │⠀⠀⠀⠀⣀⣠⣄⣤⣭⣿⣿⣿⣿⣿⣿⣿⣿⣯⣯⣯⣭⣽⣿⣿⣿⣿⣿⣯⣭⣍⡙⠛⠝⠉⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠠⠴⠿⢯⠭⠿⠯⣭⣷⡾⠿⠿⠿⣿⢿⡿⡻⠿⡟⠛⢛⣛⠯⠭⠒⠒⠉⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⣀⣀⣄⠀⠀⠀⢀⣀⡠⠤⠔⠒⠊⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-     0 │⠀⠀⢀⣀⣴⣶⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣻⣷⣄⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⡀│             
+   6.9 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣠⣴⡮⠟⠀⠀│ sepal_width 
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⠀⠀⠀⣀⣀⣤⣴⣶⣿⣟⣯⣥⣔⣲⠊⠉│ petal_length
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣔⢾⣥⣤⣶⣿⣿⣿⣿⠿⠛⠛⠋⠉⠀⠀⠀⠀⠀⠀│ petal_width 
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣠⣤⣾⣿⣿⣿⣿⣿⣿⣿⣿⣛⣗⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ species     
+       │⠀⠀⠀⠀⠀⠀⠀⠀⣀⣀⠤⠔⠒⣋⡻⠭⠛⣩⡿⣟⣷⣽⣫⣥⣒⣲⣭⣶⣒⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⠈⠉⠀⠀⠀⢀⣉⡟⣛⣿⣝⣻⣿⣿⣿⠿⢿⣿⡿⠿⣛⠤⠊⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⠀⢀⣠⣤⣿⣷⣿⣿⣿⣿⣿⠿⠿⠛⠋⠉⠁⣀⠔⠊⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣠⢀⣠│             
+       │⠀⢀⣀⣭⣿⣿⣿⣿⣿⣿⣿⣿⣽⣖⣋⣙⣀⣀⣤⣤⣤⣔⣮⣤⣄⣀⣀⣤⣤⣔⣶⣾⡳⠮⠝⠓⢊⢽⠋⠀│             
+       │⠒⢷⠿⠿⢛⠟⠛⠙⠑⠚⠉⠀⠲⣶⣿⣿⣶⣿⣷⣿⣿⣷⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣶⣶⣷⣾⠀⠀│             
+       │⠀⠸⡠⠔⠁⠀⢠⡤⣴⣶⣿⣿⠿⣿⣿⣿⢿⣿⣿⣿⣿⣿⣟⣟⣉⣉⣩⣛⣛⣭⣭⣥⣤⣤⣔⣒⣒⡚⠀⠀│             
+       │⠀⠀⠁⠀⠀⢀⡀⠨⢞⠊⢉⡠⠔⠉⠤⠴⢥⣴⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣷⣶⣶⣶⣶⣿⣿⡭⠤⠤│             
+       │⠀⣀⣀⣄⣤⣤⣽⣿⣿⣿⣿⣿⣿⡿⣿⣿⣽⣽⣯⣭⣿⣿⣿⣿⣿⣿⣿⣭⣭⣉⠛⠛⠝⠉⠀⠀⠀⠀⠀⠀│             
+       │⠤⠿⠿⡯⠽⠿⢭⣽⣶⡾⠿⠿⠿⣿⠿⣿⢟⠿⢻⠟⠛⣛⣛⠯⠭⠝⠒⠊⠉⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⢀⣀⡠⣀⠀⠀⠀⢀⣀⡠⠤⠤⠒⠒⠉⠉⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+     0 │⣀⣴⣶⣾⣿⣷⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣦⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀⣀│             
        └────────────────────────────────────────┘             
-       4                                        8
+       4.3                                    7.9
                      sepal_length
diff --git a/test/fixtures/iris-scatter.txt b/test/fixtures/iris-scatter.txt
index 6e85680..148ae10 100644
--- a/test/fixtures/iris-scatter.txt
+++ b/test/fixtures/iris-scatter.txt
@@ -1,20 +1,20 @@
                      IRIS-SCATTER
        ┌────────────────────────────────────────┐             
-   6.9 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠄⠃⠀⠀│ sepal_width 
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⠀⠀⠀⠀⠀⠀⠀⡄⠂⠄⠀⠀⠄⠀⠁│ petal_length
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠀⠀⡀⡀⠂⠀⡆⠁⠄⠈⠀⠂⠀⠀⠀⠀⠀⠀⠀│ petal_width 
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⡀⡀⠀⠂⡀⠃⡅⠀⠄⠁⡂⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ species     
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠐⠀⠁⠀⠄⢕⠀⠄⡃⠀⠀⠀⡁⠄⠂⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠁⠀⠀⠀⠀⠁⣊⠀⡃⠀⡀⠉⠀⠅⠂⠅⠙⠀⠂⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠀⢅⠀⡄⡮⠀⠅⠇⠀⠒⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠄⠀⠄│             
-       │⠀⠀⠀⠀⠀⠨⠀⠠⠀⡀⣷⠀⠆⠀⠄⠊⠀⠂⠀⠀⠄⠀⠄⡄⠀⠀⠀⡀⠀⠀⠀⠀⠁⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠐⠀⠇⠘⠀⠑⠀⠂⠓⠀⠀⠀⠂⢰⠀⡆⡀⠃⢶⠀⡄⡄⡇⡳⠀⠂⡃⠃⠑⠀⠃⠄⡀⠀⠂⡂⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⡄⠠⠀⠁⠀⠀⡮⠀⠆⡃⠀⠑⠀⠀⡅⠁⠀⠀⡄⠀⠀⠀⠀⠄⠀⠀⠀⠀⠂⠀⠀│             
-       │⠀⠀⠀⠀⠀⠁⠀⢀⠀⠀⢅⠀⠀⠀⠀⠡⠀⠄⡀⠀⠁⠀⠁⡁⡃⠅⠀⠃⠃⠃⠐⠀⠀⠀⡀⠀⠂⠅⠀⠄│             
-       │⠀⠀⠀⠀⡀⢠⠀⢤⠀⡆⣴⠀⡤⠀⠆⡠⠀⠆⠀⠅⢍⠀⠅⠅⠅⢅⠀⡇⡀⠄⡀⠀⠅⠁⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠠⠀⠁⢁⠀⠁⠀⡀⡣⠀⠀⠀⠁⡯⠀⡃⡂⠀⡘⠀⠁⠁⠁⠈⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
-     0 │⠀⠀⢀⠀⡄⣲⠀⣴⠀⡄⣿⠀⣤⠀⡅⣄⠀⡃⡄⡀⣀⠀⡀⡀⡀⣀⠀⡀⡀⡀⣀⠀⡀⡀⡀⠀⡀⡀⠀⡀│             
+   6.9 │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠠⠘⠀⠀│ sepal_width 
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡄⠂⠄⠀⠀⠠⠀⠈│ petal_length
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠀⠀⡀⡀⠂⠀⢰⠈⠠⠀⠀⠁⠂⠀⠀⠀⠀⠀⠀⠀│ petal_width 
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⢀⢀⠀⠀⠂⡀⠃⡅⠀⠠⠈⢐⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│ species     
+       │⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠂⠈⠀⠠⠨⢐⠀⠄⡃⠀⠀⠀⢈⠠⠐⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⠈⠀⠀⠀⠀⠀⠁⡂⡁⢘⠀⢀⠈⠈⠀⠅⠂⠅⠁⠘⠐⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⠀⠀⢠⠀⠅⡀⡄⡆⠅⠨⠸⠀⠐⠐⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠠⠀⠠│             
+       │⠀⠀⠀⠅⠀⠠⢀⢸⢰⠀⠆⠀⠄⠂⠁⠐⠀⠀⠠⠀⠀⠄⡄⠀⠀⠀⢀⠀⠀⠀⠀⠀⠁⠀⠀⠀⠀⠀⠀⠀│             
+       │⠂⠇⠀⠃⠁⠐⠐⠘⠐⠀⠀⠀⠂⠀⡆⢰⢀⠘⠰⢰⠀⡄⡄⡇⡃⠰⠐⢘⠘⠈⠀⠂⠃⠄⡀⠀⠐⢐⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⢠⠀⠠⠀⠁⠀⠀⡆⠅⠰⢘⠀⠈⠐⠀⠀⡅⠁⠀⠀⢠⠀⠀⠀⠀⠀⠄⠀⠀⠀⠀⠐⠀⠀│             
+       │⠀⠀⠁⠀⠀⢀⠀⠨⢀⠀⠀⠀⠀⠁⠄⠠⢀⠀⠈⠀⠀⠁⡁⡃⠅⠀⠘⠘⠘⠀⠀⠂⠀⠀⡀⠀⠐⠨⠀⠠│             
+       │⠀⡀⠀⡄⠄⢠⢰⢠⢰⠀⡄⠄⠆⡀⠄⠰⠀⠨⠨⢈⠀⠅⠅⠅⠅⢀⢸⢀⠠⢀⠀⠀⠅⠁⠀⠀⠀⠀⠀⠀│             
+       │⠄⠁⠁⡀⠁⠀⢀⢘⠠⠀⠀⠀⠁⡇⠅⢘⢐⠀⢀⠘⠀⠁⠁⠁⠀⠈⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+       │⠀⠀⠀⠀⠀⠀⠀⠠⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀│             
+     0 │⡀⡄⡂⡆⡄⢰⢠⢸⢸⠀⡄⡄⡅⡄⡀⢘⢠⢀⢀⢀⠀⡀⡀⡀⡀⢀⢀⢀⢀⢀⠀⡀⡀⡀⡀⠀⢀⢀⠀⢀│             
        └────────────────────────────────────────┘             
-       4                                        8
+       4.3                                    7.9
                      sepal_length