Nrthugu

I am using python to stream and plot some sensor data from an arduino to my pc.
I want the graph to have a legend with some values (that I also stream from my serial connection of course) but in all examples I found there was a big space at the left side of the legend.

How can I remove it? (Or get the same output using something else)

This is my code:

#!/usr/bin/python



import matplotlib.pyplot as plt

import time

import numpy as np

from scipy.interpolate import spline

import matplotlib.patches as mpatches



# Local variables

x = 

y = 



# Open the data file for reading lines

datafile = open('./plotfiles/forceplot.txt', 'r')

sepfile = datafile.read().split('n')

datafile.close()



# Create a canvas to place the subgraphs

canvas = plt.figure()

rect = canvas.patch

rect.set_facecolor('white')



# Iterate through the lines and parse them

for datapair in sepfile:

    if datapair:

        xypair = datapair.split(',')

        x.append(int(xypair[0]))

        y.append(int(xypair[1]))



x_sm = np.array(x)

y_sm = np.array(y)



x_smooth = np.linspace(x_sm.min(), x_sm.max(), 200)

y_smooth = spline(x, y, x_smooth)



# Define the matrix of 1x1 to place subplots

# Placing the plot1 on 1x1 matrix, at pos 1

sp1 = canvas.add_subplot(1,1,1)

#sp1.plot(x, y, 'red', linewidth=2)

sp1.plot(x_smooth, y_smooth, 'red', linewidth=1)



# Colorcode the tick tabs 

sp1.tick_params(axis='x', colors='red')

sp1.tick_params(axis='y', colors='red')



# Colorcode the spine of the graph

sp1.spines['bottom'].set_color('r')

sp1.spines['top'].set_color('r')

sp1.spines['left'].set_color('r')

sp1.spines['right'].set_color('r')



# Put the title and labels

sp1.set_title('matplotlib example 1', color='red')

sp1.set_xlabel('matplot x label', color='red')

sp1.set_ylabel('matplot y label', color='red')



# Show the plot/image

time = 'time: 00:23'

s = 3

sh = "success hits: "+str(s)

legend_dict = { sh: sh, 'total hits' : '5', time : time}

patchList=

for key in legend_dict:

    data_key = mpatches.Patch(color='None', label=key)

    patchList.append(data_key)



plt.legend(handles=patchList)



plt.tight_layout()

plt.grid(alpha=0.8)

plt.savefig("example6.eps")

plt.show()

And this is the output:

Since the color is None, it displays empty space. If you use text:

text(x, y,'time: 00:23nsuccess hits: 3ntotal hits: 5', horizontalalignment='center',
verticalalignment='center')