I'm trying to print a logistic differential equation and I'm pretty sure the equation is written correctly but my graph doesn't display anything.
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
def eq(con,x):
return con*x*(1-x)
xList = np.linspace(0,4, num=1000)
con = 2.6
x= .4
for num in range(len(xList)-1):
plt.plot(xList[num], eq(con,x))
x=eq(con,x)
plt.xlabel('Time')
plt.ylabel('Population')
plt.title("Logistic Differential Equation")
plt.show()
You get nothing in your plot because you are plotting points.
In plt you need to have x array and y array (that have the same length) in order to make a plot.
If you want to do exactly what you are doing I suggest to do like this:
import matplotlyb.pyplot as plt # just plt is sufficent
import numpy as np
def eq(con,x):
return con*x*(1-x)
xList = np.linspace(0,4, num=1000)
con = 2.6
x= .4
y = np.zeros(len(xList)) # initialize an array with the same lenght as xList
for num in range(len(xList)-1):
y[num] = eq(con,x)
x=eq(con,x)
plt.figure() # A good habit is always to use figures in plt
plt.plot(xList, y) # 2 arrays of the same lenght
plt.xlabel('Time')
plt.ylabel('Population')
plt.title("Logistic Differential Equation")
plt.show() # now you should get somthing here
I hope that this helps you ^^
I am trying to plot vehicle position (coordinates - x,y) against time(1s,2s,3s...). I tried with matplotlib but could not succeed. I am new in python. Could anyone help me please.
My code:
import matplotlib.pyplot as plt
import numpy as np
coordinate = [[524.447876,1399.091919], [525.1377563,1399.95105], [525.7932739,1400.767578], [526.4627686,1401.601563],
[527.2360229,1402.564575], [527.8989258,1403.390381], [528.5689697,1404.224854]]
timestamp =[0,0.05,0.1,0.15,0.2,0.25,0.3]
plt.plot(coordinate,timestamp)
Plot comes like: But this is wrong one. I did wrong.
Plot supposed to become, in particular, timestamp (1s) the vehicle position is (x,y). So there should be one line just like vehicle trajectory.
Thanks.
I believe this is the output you're looking for:
import matplotlib.pyplot as plt
import numpy as np
coordinate = [[524.447876,1399.091919],
[525.1377563,1399.95105],
[525.7932739,1400.767578],
[526.4627686,1401.601563],
[527.2360229,1402.564575],
[527.8989258,1403.390381],
[528.5689697,1404.224854]]
v1 = [y[1] for y in coordinate]
v2 = [y[0] for y in coordinate]
x = [0,0.05,0.1,0.15,0.2,0.25,0.3]
plt.plot(x,v1)
plt.plot(x,v2,'--')
plt.ylim(0,1500)
plt.show()
Does something simple like this meet your needs:
import matplotlib.pyplot as plt
coordinates = [
(524.447876,1399.091919),
(525.1377563,1399.95105),
(525.7932739,1400.767578),
(526.4627686,1401.601563),
(527.2360229,1402.564575),
(527.8989258,1403.390381),
(528.5689697,1404.224854),
]
timestamp = [0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3]
x, y = zip(*coordinates)
ax = plt.axes(projection="3d")
ax.plot(x, y, timestamp);
plt.show()
Matplotlib will let you rotate the image with the mouse to view it from various angles.
Hi I think the problem over here is that you are using a two-dimensional list, so matplotlib plots the coordinates and not the timestamp.
Code:
import matplotlib.pyplot as plt
import numpy as np
coordinate = np.array([[524.447876,1399.091919], [525.1377563,1399.95105], [525.7932739,1400.767578], [526.4627686,1401.601563], [527.2360229,1402.564575], [527.8989258,1403.390381], [528.5689697,1404.224854]])
timestamp =np.array([0,0.05,0.1,0.15,0.2,0.25,0.3])
plt.plot(coordinate)
Output:
You have to convert it into a single dimension list like this:
coordinate_new = np.array([524.447876,525.1377563,1399.95105, 525.7932739,1400.767578, 526.4627686,1401.601563])
timestamp =np.array([0,0.05,0.1,0.15,0.2,0.25,0.3])
plt.plot(coordinate_new, timestamp)
Then the output will be:
Hope I could help!!
If you want to plot it in 3-d, here is what you can do:
import matplotlib.pyplot as plt
#importing matplotlib
fig = plt.figure() #adding figure
ax_3d = plt.axes(projection="3d") #addign 3-d axes
coordinate_x = [524.447876, 525.137756, 525.7932739, 526.4627686, 527.2360229, 527.8989258, 528.5689697]
coordinate_y = [1399.091919, 1399.95105,1400.767578,1401.601563,1402.564575,1403.390381,1404.224854]
timestamp =[0,0.05,0.1,0.15,0.2,0.25,0.3]
# defining the variables
ax.plot(coordinate_x, coordinate_y, timestamp)
#plotting them
Output:
All the Best!
I'm relatively new to Python.
I'm trying to plot exponential term value ranging between 0 and 100.
There is no error indicated with the code but the Plot has no legend(line).
Kindly help me.
Thank you.
import math
import matplotlib.pyplot as plt
for i in range (0,101):
m = math.exp(i)
print("For i = ",i)
print("(e^i) = ",m)
plt.plot(i,m,'b--',linewidth=3)
plt.ylabel('e^i')
plt.xlabel('i')
plt.show()
You can change your code in this way:
import math
import matplotlib.pyplot as plt
l = list(range (0,101))
m_l = []
for i in l:
m = math.exp(i)
print("For i = ",i)
print("(e^i) = ",m)
m_l.append(m)
plt.plot(l,m_l,'b--',linewidth=3)
plt.ylabel('e^i')
plt.xlabel('i')
plt.legend(['m_l'])
plt.show()
With your code, you were plotting just the last values of i and m
I want to plot ECG graph using matplotlib . y values from a file having float values and x value is incrementing(ie x ranges from 1 to 1000). went through tutorials and couldn't find any solutions.
Demo Code
import numpy as np
import matplotlib.pyplot as plt
import random
import pickle
#Y Axis : Generate 1000 random numbers
yAxisNumbers = np.random.uniform(1,100,1000)
#Save numbers to a file for demo purpose
with open('numpyData.txt', 'wb') as myFile:
pickle.dump(yAxisNumbers,myFile)
#X Axis :Generate 1000 random numbers
xNumbers = [ x for x in range(1000)]
#Load file data to a list
with open('numpyData.txt', 'rb') as aFile:
yNumbers = pickle.load(aFile)
#Plot and label Graph
plt.plot(xNumbers,yNumbers)
plt.ylabel("Random Float Numbers")
plt.xlabel("Number Count")
plt.title("ECG Graph")
plt.show()
Graph
Here's a minimal answer, based on the scant details provided.
import numpy as np
import matplotlib.pyplot as plt
plt.ion()
Y = np.loadtxt(filename, other needed options)
plt.plot(np.arange(len(Y))+1,Y)
import numpy as np
import pylab as p
aa=np.loadtxt('....your file ....')
x,y= aa.T # transpose data into 2 columns, assuming you have 2 columns
p.plot(x,y)
p.show()
I would like to plot my intermediate results and want to see how is the algorithm progressing. I have posted a demo code too. Lets say my algorithm goes for 20 epochs and I want to plot the result of every epoch in a same file. I tried with following demo code. But I can not see any plot on a.png.
Could someone help me how could I do it?
import matplotlib.pylab as plt
import numpy as np
for i in range(20):
y = np.random.random()
plt.plot(i, y)
plt.savefig('a.png')
You have to provide the whole history in your variables e.g. as a list:
import matplotlib.pylab as plt
import numpy as np
# creates two lists with the same length
x = range(20)
y = [0] * 20
for i in x:
y.insert(i, np.random.random())
plt.plot(x, y)
plt.savefig('plot_%d.png' % i)