Plotting multiple lines to a single Python figure

Question

This is my first Stack Overflow question so please excuse me if the formatting of this question does not follow the conventions of the Stack Overflow community.

My question is how can you (if possible) add a line to an existing Python figure using pyplot? Essentially, what I want to accomplish is I want to compile and run my code and have that generate a figure with a line on it. Then, what I want to do is change some data in the code, compile and run the code again, and then have the line generated from this running of the code show up on the already existing figure.

fig=plt.figure(figsize=(20,10))
time= np.array(range(0, time_steps+1)) 
sigma_11=Q[:, :, :, 0]
sigma_22=Q[:, :, :, 1]
sigma_12=Q[:, :, :, 2]
vel_x=Q[:, :, :, 3]
vel_y=Q[:, :, :, 4]
stiffness_mat=np.mat([[lamda+2*mu, lamda, 0],
                    [lamda, lamda+2*mu, 0],
                    [0, 0, 2*mu]])

Energ_P=np.zeros((time_steps+1))  
Energ_K=np.zeros((time_steps+1))
Energy_tot=np.zeros((time_steps+1))     
    for n in  range(0, time_steps+1):
Energ_P[n]=(Energy_P(stiffness_mat, Q[:, :, n, 0:3]))
Energ_K[n]=(Energy_K(Q[:, :, n, 3:5]))
Energy_tot[n]=Energ_P[n]+Energ_K[n]

sub1=fig.add_subplot(1, 2, 1)  
sub1.set_title('stress-time')
sub1.plot(time*del_t, sigma_11[bar_cells_x, bar_cells_y, :], label='stress_1')
sub1.plot(time*del_t, sigma_11[bar_cells_x/2, bar_cells_y/2, :], label='stress')
sub1.set_ylabel('sigma_11 [Pa]')
sub1.set_xlabel('time [s]')
sub1.legend(loc='best', fontsize='10')

plt.tight_layout()
plt.show()

I haven't really tried much of anything to solve this yet, save running the code multiple times. However, when I do this, all I end up doing is generating multiple figures.

What have you tried so far? Where are you running into problems? Let's see some code!!! — Matt Messersmith, Jun 24 '16 at 14:42
Possible duplicate of [Adding an arbitrary line to a matplotlib plot in ipython notebook](http://stackoverflow.com/questions/12864294/adding-an-arbitrary-line-to-a-matplotlib-plot-in-ipython-notebook) — Destrif, Jun 24 '16 at 14:44
Despite it's your first question, you should read and follow the conventions. Please, see [help page on asking questions](http://stackoverflow.com/help/mcve) — Vladimir Vagaytsev, Jun 24 '16 at 14:50
Your code is not working for the reason `NameError: name 'time_steps' is not defined`. — SparkAndShine, Jun 24 '16 at 15:01
You should tag your question with the plotting library's name that you are using. — martineau, Jun 24 '16 at 15:10

score 1 · Answer 1 · edited Jun 20 '20 at 09:12

1

Try adding the num argument to plt.figure. In other words, replace fig=plt.figure(figsize=(20,10)), with fig=plt.figure(num=1, figsize=(20,10)).

From the docs,

num : integer or string, optional, default: none

If not provided, a new figure will be created, and the figure number will be incremented.

edited Jun 20 '20 at 09:12

Community

1
1

answered Jun 24 '16 at 18:40

lanery

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Plotting multiple lines to a single Python figure

1 Answers1