CODEWITHSUNDEEP
pythonarraysmatplotlib
tfinan
tfinan

Reputation: 31

How to plot many datasets from numpy list with matplotlib

I'm new to Python and struggling with plotting many curves on one graph with matplotlib.

I have 50 data files. I've read them all in and stored them in a 3D numpy list. First dimension is the filenumber, 2nd dimension is the time, 3rd dimension is the parameter being measured (time, pressure, ...). For a single file the data might look like this:

(time) (pressure) 1 3.4 2 5.1 3 5.1 4 5.1 5 7.8

I want to plot all fifty time vs. pressure curves on one graph. What I have so far is:

plt.plot(\
    clipData[0,:,0], clipData[0,:,1],\
    clipData[1,:,0], clipData[1,:,1],\
    clipData[2,:,0], clipData[2,:,1])
plt.show()

This works fine for the first three curves, but I figure there must be a way to do this with out manually generating the list out to 50. I thought about using a loop to build the list as a long string and then shoving this string into plot(). 

guts = 'clipData[0,:,0], clipData[0,:,1]'
plt.plot(guts)
plt.show

But my simple test made it clear I was doing something very wrong.

Any help would be appreciated, I'm sure there's an elegant way to do this.

Upvotes: 2

Views: 148

Answers (3)

Stop harming Monica
Stop harming Monica

Reputation: 12590

You can pass two 2D arrays to plot. Each column in the first array will be plotted against the corresponding column of the second array.

plt.plot(clipData[:, :, 0].T, clipData[:, :, 1].T)

Plotting in this way you are somewhat limited when specifying line properties, in particular you can't pass a label for each line. For full control over line properties plotting in a loop can be more convenient.

Upvotes: 1

Chuck
Chuck

Reputation: 3852

for i in range(0,len(clipData)):
    plt.plot(clipData[i,:,0],clipData[i,:,1])
plt.show()

This way your plotting routine will run for any length of clipData or if you change it in the future.

Upvotes: 0

Dadep
Dadep

Reputation: 2788

Maybe something like : 

for i in range(50):
    plt.plot(clipData[i,:,0], clipData[i,:,1])
plt.show()

Because when you use guts = 'clipData[0,:,0], clipData[0,:,1]' guts is just a string which cannot be plotted.

Upvotes: 1

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