exponential trend example grafica

Author: monkstone

external_library/java/grafica/exponential_trend.rb

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+# frozen_string_literal: true
+
+load_library 'grafica'
+java_import 'grafica.GPointsArray'
+java_import 'grafica.GPlot'
+java_import 'java.util.Random'
+
+N_POINTS = 1_000
+attr_reader :plot, :log_scale, :random, :points
+
+def settings
+ size(450, 450)
+end
+
+def setup
+ sketch_title 'Exponential Trend'
+ @random = Random.new
+ # Prepare the points for the plot
+ @points = GPointsArray.new(N_POINTS)
+ @plot = GPlot.new(self)
+ puts plot.inspect
+ @log_scale = false
+ N_POINTS.times do
+ x_value = rand(10..200)
+ y_value = 10**(0.015 * x_value)
+ x_error = 2 * random.next_gaussian
+ y_error = 2 * random.next_gaussian
+ points.add(x_value + x_error, y_value + y_error)
+ end
+ # Create the plot
+ plot.set_pos(25, 25)
+ plot.set_dim(300, 300)
+ # or all in one go
+ # plot = GPlot.new(self, 25, 25, 300, 300)
+ # Set the plot title and the axis labels
+ plot.set_title_text('Exponential law')
+ # NB: cannot use snake for getXAxis etc
+ plot.getXAxis.set_axis_label_text('x')
+ toggle_y_axis
+ # Add the points to the plot
+ plot.set_points(points)
+ plot.set_point_color(color(100, 100, 255, 50))
+end
+
+def draw
+ background(150)
+ plot.begin_draw
+ plot.draw_background
+ plot.draw_box
+ plot.drawXAxis
+ plot.drawYAxis
+ plot.draw_top_axis
+ plot.draw_right_axis
+ plot.draw_title
+ plot.draw_points
+ plot.end_draw
+end
+
+def toggle_y_axis
+ y_axis = plot.getYAxis
+ if log_scale
+ plot.set_log_scale('y')
+ y_axis.set_axis_label_text('log y')
+ else
+ plot.set_log_scale('')
+ y_axis.set_axis_label_text('y')
+ end 
+end
+
+def mouse_clicked
+ @log_scale = !log_scale
+ toggle_y_axis
+end