add real-time plotting program

plot.py

@@ -0,0 +1,40 @@
+import asyncio
+from PyQt5 import QtCore, QtGui, QtWidgets
+import pyqtgraph
+import quamash
+import atexit
+
+async def task(mw):
+    widget = pyqtgraph.PlotWidget()
+    mw.setCentralWidget(widget)
+    mw.show()
+
+    process = await asyncio.create_subprocess_shell("cargo run --release",
+        stdout=asyncio.subprocess.PIPE)
+    data = []
+    while True:
+        line = await process.stdout.readline()
+        if not line:
+            print("input process died")
+            break
+        number = int(line.decode().strip())
+        data.append(number)
+        widget.clear()
+        widget.plot(data)
+
+
+
+def main():
+    app = QtWidgets.QApplication(["Plot"])
+    loop = quamash.QEventLoop(app)
+    asyncio.set_event_loop(loop)
+
+    mw = QtWidgets.QMainWindow()
+    mw.showMaximized()
+
+    atexit.register(loop.close)
+    asyncio.ensure_future(task(mw))
+    loop.run_forever()
+
+    
+main()