Pyplot refuses to show grid

Question

I have a python script that has 3 functions that plot data. 2 of them show gridlines by using ax.grid(b=True). One however, doesn't. Even after I spammed ax.grid(b=True) all over the place... I must be doing something wrong, but what?

def plotMSEProgress(times, bestScores, scores, xsplit=0, window=1): plot, ax = plt.subplots(figsize=(20,10), num=1) ax.grid(b=True, which='both') # plot = plt.figure(window) plt.ion() plt.minorticks_on() ax.grid(b=True, which='both') plt.show() plt.clf() if xsplit: plt.axvline(x=xsplit, color='g') plot = plt.plot_date(times, bestScores, '-', label="best score") plot = plt.setp(plot, color='y', linewidth=1.0) plot = plt.plot_date(times, scores, '-', label="score") plot = plt.setp(plot, color='b', linewidth=1.0) ax.grid(b=True, which='both') plt.xlabel('time') plt.ylabel('MSE') plt.suptitle('MSE over time', fontsize=16) plt.legend() ax.grid(b=True, which='both') plt.draw() ax.grid(b=True, which='both') plt.pause(0.001) ax.grid(b=True, which='both') plt.plot() ax.grid(b=True, which='both')

Maybe it has something to do with plt.ion() ? Because I don't have that in the othe plotting functions that do show the grid.

I already tried this and this by adding the plt.minorticks_on(), but to no avail sadly.

Is there something obvious I'm missing? Or is there some other hidden incompatibility?

Screenshot of plot as requested:

Please include some example data such that the above function will run and generate plots. — Nathaniel
– Nathaniel, Commented Mar 25, 2019 at 20:52
What I meant was include the values of times, scores, and bestScores. — Nathaniel
– Nathaniel, Commented Mar 25, 2019 at 21:15

Nathaniel · Accepted Answer · 2019-03-25 22:12:02Z

Add in a call to plt.grid() inside your function, and remove extraneous code:

import matplotlib.pyplot as plt import datetime def plotMSEProgress(times, bestScores, scores, xsplit=0, window=1): plot, ax = plt.subplots(figsize=(20,10), num=1) plt.ion() plt.clf() if xsplit: plt.axvline(x=xsplit, color='g') plot = plt.plot_date(times, bestScores, '-', label="best score") plot = plt.setp(plot, color='y', linewidth=1.0) plot = plt.plot_date(times, scores, '-', label="score") plot = plt.setp(plot, color='b', linewidth=1.0) plt.minorticks_on() plt.grid(which='major') plt.grid(which='minor', linestyle = ':') plt.xlabel('time') plt.ylabel('MSE') plt.suptitle('MSE over time', fontsize=16) plt.legend(loc=2) plt.draw() plt.pause(0.001) # Generate example data base = datetime.datetime.today() times = [base + datetime.timedelta(seconds=x) for x in range(0, 100)] scores = np.random.rand(len(times))*30 bestScores = np.random.rand(len(times))*5 # Generate plot dynamically for i in range(len(times)): plotMSEProgress(times[0:i], bestScores[0:i], scores[0:i], xsplit=0, window=1)

This code generates a plot and dynamically updates it, all while showing the gridlines the whole time.

I'm not sure what kind of functionality you're trying to get out of plt.ion(), but this code will give you the gridlines successfully.
plt.ion() is used to make plt.plot() non-blocking. It allows my script to continously run, and update the graph after each iteration. Strangely enough, your code only seems to work with the last iteration of my script.
I have updated my answer to try and address this. Since I cannot run your code in a loop like you seem to be using it, I can't test it for that specific case. Can you please update your question to include the iteration loop you speak of?
@Opifex I have added an example loop which shows dynamic plotting of the data. Please let me know if this adequately addresses your question.
I used your original answer, and did some tinkering and finally got it working. I moved clf() to the top of the function, and grid() right below subplots(). This seems to have fixed it (or I did something else while tinkering that solved it). I'm not sure whose answer to accept now though, because Meng's was also correct in a way (even though it didn't work for my purpose), but more importantly: his remarks were very valuable I think.

Community · Accepted Answer · 2020-06-20 09:12:55Z

I think you have some unnecessary codes, which creates multiple plots. The first plot you had is empty but with grids and the later plots contain the data, but not the grids.

Try the code below. I commented some of your scripts and made it work.

def plotMSEProgress(times, bestScores, scores, xsplit=0, window=1): plot, ax = plt.subplots(figsize=(20,10), num=1) ax.grid(b=True, which='both') # plot = plt.figure(window) plt.ion() plt.minorticks_on() ax.grid(b=True, which='both') # plt.show() # plt.clf() if xsplit: plt.axvline(x=xsplit, color='g') plot = plt.plot(times, bestScores, '-', label="best score") # you can change it back to plot_date plot = plt.setp(plot, color='y', linewidth=1.0) plot = plt.plot(times, scores, '-', label="score") # you can change it back to plot_date plot = plt.setp(plot, color='b', linewidth=1.0) ax.grid(b=True, which='both') plt.xlabel('time') plt.ylabel('MSE') plt.suptitle('MSE over time', fontsize=16) plt.legend() ax.grid(b=True, which='both') plt.draw() ax.grid(b=True, which='both') plt.pause(0.001) ax.grid(b=True, which='both') # plt.plot() ax.grid(b=True, which='both') times = list(range(0,100)) bestScores = list(range(100,200)) scores = list(range(150,250)) xsplit=0 window=1 plotMSEProgress(times, bestScores, scores, xsplit=0, window=1)

I tried your code and it seems to work, but when it gets redrawn, the previous plot doesn't dissapear. It seems like it is overlayed on eachother. see: imagehost.cc/image/k20gS I tried re-adding plt.clf(), but then the grid also dissapears again? =/ Any clue how I would fix this?

Collectives™ on Stack Overflow

Pyplot refuses to show grid

2 Answers 2

6 Comments

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

1 Comment

Linked

Related