#!/usr/bin/env python
"""
Author: Flavio Codeco Coelho
License: GPL
Stripchart module for vpython
Features:
-user defined number of channels
"""
import psyco
import time
from visual import *
from visual.text import *
from RandomArray import random
from psyco.classes import *
psyco.full()
class Strip:
"""
Stripchart object.
"""
def __init__(self, nch=1, xlabel='t(s)',ylabel='V'):
self.scene = display(title="Stripchart Recorder",width=600,height=400, uniform=0, ambient=1,autoscale=1)
#create the curves
self.channels = self.addch(nch)
self.gridon = True
self.grid = frame() #collection of horizontal grid lines
self.ticklabels=frame()#collection of labels
self.xlabel = label(frame=self.grid,pos=(9,-9,0),text=xlabel,color=color.orange,box=0, line=0)
self.ylabel = label(frame=self.grid,pos=(-9,9,0),text=ylabel,color=color.orange,box=0,line=0)
self.drawGrid()
self.drawTickLabels(range(-10,10),range(-10,10))
def addch(self, nch=1):
"""
Creates a channel object (curve)
nch is the number of channels.
"""
col = [color.white,color.blue,color.red,color.green,color.yellow,color.cyan,color.magenta, color.orange]
tplch = tuple([curve(radius=0, color=col[n%len(col)])for n in xrange(nch)])
return tplch
def toggleGrid(self):
"""
Toggle visibility of gridlines
"""
r = len(self.grid.objects)
if self.gridon:
for i in range(r):
self.grid.objects[0].visible = 0
self.gridon = False
else:
self.drawGrid()
self.gridon = True
pass
def drawGrid(self):
"""
draw grid lines
"""
hrng = int(self.scene.range[1])
vrng = int(self.scene.range[0])
[curve(frame=self.grid,pos=[(-vrng,i),(vrng,i)],color=color.white) for i in xrange(-hrng, hrng, hrng*2/10)]
[curve(frame=self.grid,pos=[(j,-hrng),(j,hrng)],color=color.white) for j in xrange(-vrng, vrng, vrng*2/10)]
def drawTickLabels(self,xticks,yticks):
"""
Draw x and y tick labels
"""
xticks2 = array([round(i,2) for i in xticks])
yticks2 = array([round(i,2) for i in yticks])
labidx = range(0,len(xticks2),len(xticks2)/10) #indices to the labels to be plotted
Pos = range(-10,10,2) #position of the ticklabels within the frame coordinates
#List comprehensions to draw ticklabels. [(xticks,yticks) for i in xrange(len(Pos))]
# Not as clear as a regular "for" but much faster...
[label(frame=self.ticklabels,pos=(Pos[i],-8,0),text=str(xticks2[labidx[i]]),color=color.orange,box=0,line=0) for i in xrange(len(Pos))] #x ticklables
[label(frame=self.ticklabels,pos=(-8,Pos[i],0),text=str(yticks2[labidx[i]]),color=color.orange,box=0,line=0) for i in xrange(len(Pos))] #y ticklabels
def updateTicks(self,xticks,yticks):
"""
Update tick labels values
"""
xticks2 = array([round(i,2) for i in xticks])
yticks2 = array([round(i,2) for i in yticks])
labidx = range(0,len(xticks2),len(xticks2)/10) #indices to the labels to be plotted
Pos = range(-10,10,2) #position of the ticklabels within the frame coordinates
i = j = 0
for l in self.ticklabels.objects:
if self.ticklabels.objects.index(l) < 10: #update x axis
l.text = str(xticks2[labidx[i]])
i += 1
else: #update y axis
l.text = str(yticks2[labidx[j]])
j += 1
def plot(self,ch,point):
"""
Appends a point to the channel(curve) object ch.
Fills the scene and after it is full,
shifts the curve one step left, for each new point.
If its the first point it creates the plot.
"""
#Adjust the scene and frames vertically to folow data
if point[1] > self.scene.range[1]:
self.scene.center[1] = point[1]-9
self.grid.y = point[1]-9
self.ticklabels.y = point[1]-9
elif point[1] < -self.scene.range[1]:
self.scene.center[1] = point[1]+9
self.grid.y = point[1]+9
self.ticklabels.y = point[1]+9
#=========================================
if self.scene.kb.keys:#key trap
s = self.scene.kb.getkey() # obtain keyboard information
if s == 'g' or s == 'G':
self.toggleGrid()
# Scroll scene center right to follow data
if len(ch.x) > 0 and ch.x[-1] > 10:
# scroll center of the scene with x
new_x_center = (ch.x[0]+ch.x[-1])/2.
self.scene.center = (new_x_center,0,0)
self.updateTicks(ch.x,ch.y)
self.grid.x = new_x_center
self.ticklabels.x = new_x_center
# shift curve and append
ch.pos[:-1] = ch.pos[1:]
ch.pos[-1] = point
else:
ch.append(pos=point)
if __name__=='__main__':
st = Strip(2)
ch1 = st.channels[0]
ch2 = st.channels[1]
start = time.clock()
for i in arange(-10,200,.1):
st.plot(ch1,(i,10*sin(i),0))
st.plot(ch2,(i,10*cos(i)+random(),0))
#rate(50)#set maximum frame rate
print "frame rate: ", 1/((time.clock()-start)/210.)
