📦 add grid example

Author: cyberbit

src/examples/grid.lua

@@ -0,0 +1,50 @@
+local Plotter = require 'plotter'
+
+local termw,termh = term.getSize()
+local winPlot = window.create(term.current(), 1, 1, termw, termh, true)
+
+local plotter = Plotter(winPlot)
+
+local plotData = {}
+local gridOffsetX = 0
+local gridGapX = 20
+local value = 0
+
+-- preload chart with blank data
+for i = 1, plotter.box.width do
+    table.insert(plotData, plotter.NAN)
+end
+
+while true do
+    value = value + math.random(-90,100)
+    
+    -- push new value to end, remove first value
+    table.insert(plotData, type(value) ~= 'nil' and value or plotter.NAN)
+    table.remove(plotData, 1)
+
+    gridOffsetX = (gridOffsetX - 1) % gridGapX
+
+    plotter:clear(colors.black)
+
+    local min, max = plotter:chartLineAuto(plotData, colors.white)
+
+    -- chart grid with specified offset and styles
+    plotter:chartGrid(#plotData, min, max, gridOffsetX, colors.white, {
+        -- integer >= 1
+        xGap = gridGapX,
+
+        -- number >= 1
+        yLinesMin = 3,
+
+        -- integer >= 2
+        yLinesFactor = 2
+
+        -- effective yLinesMax: yLinesMin * yLinesFactor
+    })
+
+    winPlot.setVisible(false)
+    plotter:render()
+    winPlot.setVisible(true)
+
+    sleep(0.1)
+end