New Demo - Dual Axis bar chart

DemoPrograms/Demo_Graph_Bar_Chart_Dual_Axis.py

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+import PySimpleGUI as sg
+import random
+
+"""
+    Bar Chart - Dual Axis Version
+
+    A simple bar chart with a twist
+    If you've got 2 values to plot, this technique enables you to trivially plot them both.
+    Simply set your Graph element coordinates to be negative. Make your y=0 line run through the middle
+
+    Copyright 2022 PySimpleGUI
+"""
+
+BAR_WIDTH = 25              # width of each bar
+BAR_SPACING = 30            # space between each bar
+EDGE_OFFSET = 3             # offset from the left edge for first bar
+GRAPH_SIZE= (500,500)       # size in pixels
+
+sg.theme('Light brown 1')
+
+layout = [[sg.Text('Dual-Axis Bar Chart')],
+          [sg.Graph(GRAPH_SIZE, (0, -GRAPH_SIZE[0]//2), (GRAPH_SIZE[0]//2, GRAPH_SIZE[1]//2), k='-GRAPH-')],
+          [sg.Button('OK'), sg.T('Click to display more data'), sg.Exit()]]
+
+window = sg.Window('Bar Graph', layout, finalize=True)
+
+# get the Graph Element into a variable to make code completion easier
+graph:sg.Graph = window['-GRAPH-']
+
+while True:
+    graph.erase()
+    for i in range(8):
+        graph_value = random.randint(0, GRAPH_SIZE[1]//2)
+        graph.draw_rectangle(top_left=(i * BAR_SPACING + EDGE_OFFSET, graph_value),
+                             bottom_right=(i * BAR_SPACING + EDGE_OFFSET + BAR_WIDTH, 0),
+                             fill_color='green', line_width=0)
+
+        # get a second value and draw an inverted bar. Simply set the Y value to be negative and top to be 0
+        graph_value = random.randint(0, GRAPH_SIZE[1]//2)
+        graph.draw_rectangle(top_left=(i * BAR_SPACING + EDGE_OFFSET, 0),
+                             bottom_right=(i * BAR_SPACING + EDGE_OFFSET + BAR_WIDTH, -graph_value),
+                             fill_color='red', line_width=0)
+
+    # Normally at the top of the loop, but because we're drawing the graph first, making it at the bottom
+    event, values = window.read()
+
+    if event in (sg.WIN_CLOSED, 'Exit'):
+        break
+
+
+window.close()