This must be easy, but I can't figure how right now without using urllib module and manually fetching remote file
I want to overlay plot with remote image (let's say "http://matplotlib.sourceforge.net/_static/logo2.png"), and neither imshow() nor imread() can load the image.
Any ideas which function will allow loading remote image?
It is easy indeed:
import urllib2
import matplotlib.pyplot as plt
# create a file-like object from the url
f = urllib2.urlopen("http://matplotlib.sourceforge.net/_static/logo2.png")
# read the image file in a numpy array
a = plt.imread(f)
plt.imshow(a)
plt.show()
This works for me in a notebook with python 3.5:
from skimage import io
import matplotlib.pyplot as plt
image = io.imread(url)
plt.imshow(image)
plt.show()
you can do it with this code;
from matplotlib import pyplot as plt
a = plt.imread("http://matplotlib.sourceforge.net/_static/logo2.png")
plt.imshow(a)
plt.show()
pyplot.imread for URLs is deprecated
Passing a URL is deprecated. Please open the URL for reading and pass
the result to Pillow, e.g. with
np.array(PIL.Image.open(urllib.request.urlopen(url))).
Matplotlib suggests using PIL instead. I prefer using imageio as sugested by SciPy:
imread is deprecated in SciPy 1.0.0, and will be removed in 1.2.0. Use
imageio.imread instead.
imageio.imread(uri, format=None, **kwargs)
Reads an image from the specified file. Returns a numpy array, which
comes with a dict of meta data at its ‘meta’ attribute.
Note that the image data is returned as-is, and may not always have a
dtype of uint8 (and thus may differ from what e.g. PIL returns).
Example:
import matplotlib.pyplot as plt
from imageio import imread
url = "http://matplotlib.sourceforge.net/_static/logo2.png"
img = imread(url)
plt.imshow(img)
Related
The code below when run in jupyter notebook renders a table with a colour gradient format that I would like to export to an image file.
The resulting 'styled_table' object that notebook renders is a pandas.io.formats.style.Styler type.
I have not been able to find a way to export the Styler to an image.
I hope someone can share a working example of an export, or give me some pointers.
import pandas as pd
import seaborn as sns
data = {('count', 's25'):
{('2017-08-11', 'Friday'): 88.0,
('2017-08-12', 'Saturday'): 90.0,
('2017-08-13', 'Sunday'): 93.0},
('count', 's67'):
{('2017-08-11', 'Friday'): 404.0,
('2017-08-12', 'Saturday'): 413.0,
('2017-08-13', 'Sunday'): 422.0},
('count', 's74'):
{('2017-08-11', 'Friday'): 203.0,
('2017-08-12', 'Saturday'): 227.0,
('2017-08-13', 'Sunday'): 265.0},
('count', 's79'):
{('2017-08-11', 'Friday'): 53.0,
('2017-08-12', 'Saturday'): 53.0,
('2017-08-13', 'Sunday'): 53.0}}
table = pd.DataFrame.from_dict(data)
table.sort_index(ascending=False, inplace=True)
cm = sns.light_palette("seagreen", as_cmap=True)
styled_table = table.style.background_gradient(cmap=cm)
styled_table
As mentioned in the comments, you can use the render property to obtain an HTML of the styled table:
html = styled_table.render()
You can then use a package that converts html to an image. For example, IMGKit: Python library of HTML to IMG wrapper. Bear in mind that this solution requires the installation of wkhtmltopdf, a command line tool to render HTML into PDF and various image formats. It is all described in the IMGKit page.
Once you have that, the rest is straightforward:
import imgkit
imgkit.from_string(html, 'styled_table.png')
You can use dexplo's dataframe_image from https://github.com/dexplo/dataframe_image. After installing the package, it also lets you save styler objects as images like in this example from the README:
import numpy as np
import pandas as pd
import dataframe_image as dfi
df = pd.DataFrame(np.random.rand(6,4))
df_styled = df.style.background_gradient()
dfi.export(df_styled, 'df_styled.png')
I am a beginner to Python and experimenting with a plot. the script runs fine but plot does not show up.
the matplotlib and numpy libraries are installed.
import numpy as np
f= h5py.File('3DIMG_05JUN2021_0000_L3B_HEM_DLY.h5','r')
#Studying the structure of the file by printing what HDF5 groups are present
for key in f.keys():
print(key) #Names of the groups in HDF5 file.
# will print the variables in the file
#Get the HDF5 group
ls=list(f.keys())
print("ls")
print(ls)
tsurf = f['HEM_DLY'][:]
print("tsurf")
print(tsurf)
tsurf1=np.squeeze(tsurf)
print(tsurf1.shape)
import matplotlib.pyplot as plt
im= plt.plot(tsurf1)
#plt.colorbar()
plt.imshow(im)```
Python version is 3 running on Ubuntu
Difficult to give you the exact answer without the dataset (please update the question with the dataset), but for sure, plt.plot does not return an object that can be plotted with plt.imshow
Try instead:
ax = plt.plot(tsurf1)
plt.show()
Probably the error was on the final plot.Try this:
import numpy as np
import matplotlib.pyplot as plt
f= h5py.File('/path','r')
ls=list(f.keys())
tsurf = f['your_key_str'][:]
tsurf1=np.squeeze(tsurf)
im= plt.plot(tsurf1)
plt.show(im) # <-- plt.show() NOT plt.imshow()
The following is my code, but I can't get the plot to show on my Visual Studio Code even though I am running this on the Python Interactive Window, which should usually show a graph plot after running. The tables are showing just fine. I also do not get a default graph which pops up like it normally should. What am I doing wrong?
import yfinance as yf
import pandas as pd
import matplotlib
matplotlib.use('agg')
import matplotlib.pyplot as plt
import talib
df = pd.read_csv('filename.csv')
df = df.sort_index()
macd, macdsignal, macdhist = talib.MACD(df['Close'], fastperiod=12, slowperiod=26, signalperiod=9)
macd = macd.to_list()
macdsignal = macdsignal.to_list()
macdhist = macdhist.to_list()
df['macd'], df['macdsignal'], df['macdhist'] = macd,macdsignal,macdhist
ax = plt.gca()
print(df.columns)
df.plot(kind='line',x='Date',y='macd', color='blue',ax=ax)
df.plot(kind='line',x='Date',y='macdsignal', color='red', ax=ax)
plt.show()
The csv file has data that looks like this
The issue was with matplotlib.use('agg'), which does not support the show() function. This prevented the graph from being displayed on Visual Studio's Interactive Window. The matplotlib.use('agg') method can, however, be used for saving your graph in a .png format.
According to Matplotlib.org, agg is "the canonical renderer for user interfaces, which uses the Anti-Grain Geometry C++ library to make a raster (pixel) image of the figure". More information can be found at this link here
I'm writing Python code on Databricks to process some data and output graphs. I want to be able to save these graphs as a picture file (.png or something, the format doesn't really matter) to DBFS.
Code:
import pandas as pd
import matplotlib.pyplot as plt
df = pd.DataFrame({'fruits':['apple','banana'], 'count': [1,2]})
plt.close()
df.set_index('fruits',inplace = True)
df.plot.bar()
# plt.show()
Things that I tried:
plt.savefig("/FileStore/my-file.png")
[Errno 2] No such file or directory: '/FileStore/my-file.png'
fig = plt.gcf()
dbutils.fs.put("/dbfs/FileStore/my-file.png", fig)
TypeError: has the wrong type - (,) is expected.
After some research, I think the fs.put only works if you want to save text files.
running the above code with plt.show() will get you a bar graph - I want to be able to save the bar graph as an image to DBFS. Any help is appreciated, thanks in advance!
Easier way, just with matplotlib.pyplot. Fix the dbfs path:
Example
import matplotlib.pyplot as plt
plt.scatter(x=[1,2,3], y=[2,4,3])
plt.savefig('/dbfs/FileStore/figure.png')
You can do this by saving the figure to memory and then using the Python local file APIs to write to the DataBricks filesystem (DBFS).
Example:
import matplotlib.pyplot as plt
from io import BytesIO
# Create a plt or fig, then:
buf = BytesIO()
plt.savefig(buf, format='png')
path = '/dbfs/databricks/path/to/file.png'
# Make sure to open the file in bytes mode
with open(path, 'wb') as f:
# You can also use Bytes.IO.seek(0) then BytesIO.read()
f.write(buf.getvalue())
I want to store a matplotlib figure and load it later to use it interactively. To be more specific, I want to be able to use zoom in this figure.
I am using pickle to dump the figure handle into a file.
I then load the figure later using pickle, but the zoom does not work after loading the file even though I can use zoom in the figure before pickling it.
Here's a sample script that illustrates my problem.
import matplotlib.pyplot as plt
import pickle
import numpy as np
import os
import time
# Create Plot Data
x = np.arange(100)
# Create Figure, Axes and plot
fig1,axes1 = plt.subplots()
axes1.plot(x)
# Pickle plot
fileName = os.getcwd() + "/img"\
+ time.asctime(time.localtime()) + ".pickle"
with open(fileName,'wb') as pickle_file:
pickle.dump(fig1,pickle_file)
plt.show() # ZOOM WORKS HERE
plt.close()
# Load pickled plot
with open(fileName,'rb') as read_pickle:
fig_handle = pickle.load(read_pickle)
plt.show() # ZOOM DOES NOT WORK HERE
Zooming into the image before Pickle
Non-Zoomable image after Pickle
Version:
Python 3.7.0
Matplotlib 3.0.0
Pickle 4.0
Is this a limitation with Pickling matplotlib figure? Or is there something I can do to load/dump the figure in a zoomable way?
As #ImportanceOfBeingErnest pointed out I fixed the problem by changing my backends from MacOSX to TkAgg.
Here's what I did.
import matplotlib
matplotlib.get_backend() # Get the current backend
'MacOSX'
# Get Location where configuration file was loaded from.
matplotlib.matplotlib_fname()
'/usr/local/lib/python3.7/site-packages/matplotlib/mpl-data/matplotlibrc'
# Edit -> backend:TkAgg
matplotlib.get_backend()
'TkAgg'