I'm new to Python with a question about Cartopy being able to be used in a 3D plot. Below is an example using matplotlibBasemap.
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.basemap import Basemap
m = Basemap(projection='merc',
llcrnrlat=52.0,urcrnrlat=58.0,
llcrnrlon=19.0,urcrnrlon=40.0,
rsphere=6371200.,resolution='h',area_thresh=10)
fig = plt.figure()
ax = Axes3D(fig)
ax.add_collection3d(m.drawcoastlines(linewidth=0.25))
ax.add_collection3d(m.drawcountries(linewidth=0.35))
ax.add_collection3d(m.drawrivers(color='blue'))
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Height')
fig.show()
This creates a map within a 3D axis so that you can plot objects over the surface. But with Cartopy returns a matplotlib.axes.GeoAxesSubplot. Not clear how to take this and add to a 3D figure/axis as above with matplotlib-basemap.
So, can someone give any pointers on how to do a similar 3D plot with Cartopy?
The basemap mpl3d is a pretty neat hack, but it hasn't been designed to function in the described way. As a result, you can't currently use the same technique for much other than simple coastlines. For example, filled continents just don't work AFAICT.
That said, a similar hack is available when using cartopy. Since we can access shapefile information generically, this solution should work for any poly-line shapefile such as coastlines.
The first step is to get hold of the shapefile, and the respective geometries:
feature = cartopy.feature.NaturalEarthFeature('physical', 'coastline', '110m')
geoms = feature.geometries()
Next, we can convert these to the desired projection:
target_projection = ccrs.PlateCarree()
geoms = [target_projection.project_geometry(geom, feature.crs)
for geom in geoms]
Since these are shapely geometries, we then want to convert them to matplotlib paths with:
from cartopy.mpl.patch import geos_to_path
import itertools
paths = list(itertools.chain.from_iterable(geos_to_path(geom)
for geom in geoms))
With paths, we should be able to just create a PathCollection in matplotlib, and add it to the axes, but sadly, Axes3D doesn't seem to cope with PathCollection instances, so we need to workaround this by constructing a LineCollection (as basemap does). Sadly LineCollections don't take paths, but segments, which we can compute with:
segments = []
for path in paths:
vertices = [vertex for vertex, _ in path.iter_segments()]
vertices = np.asarray(vertices)
segments.append(vertices)
Pulling this all together, we end up with a similar result to the basemap plot which your code produces:
import itertools
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib.collections import LineCollection
import numpy as np
import cartopy.feature
from cartopy.mpl.patch import geos_to_path
import cartopy.crs as ccrs
fig = plt.figure()
ax = Axes3D(fig, xlim=[-180, 180], ylim=[-90, 90])
ax.set_zlim(bottom=0)
target_projection = ccrs.PlateCarree()
feature = cartopy.feature.NaturalEarthFeature('physical', 'coastline', '110m')
geoms = feature.geometries()
geoms = [target_projection.project_geometry(geom, feature.crs)
for geom in geoms]
paths = list(itertools.chain.from_iterable(geos_to_path(geom) for geom in geoms))
# At this point, we start working around mpl3d's slightly broken interfaces.
# So we produce a LineCollection rather than a PathCollection.
segments = []
for path in paths:
vertices = [vertex for vertex, _ in path.iter_segments()]
vertices = np.asarray(vertices)
segments.append(vertices)
lc = LineCollection(segments, color='black')
ax.add_collection3d(lc)
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Height')
plt.show()
On top of this, mpl3d seems to handle PolyCollection well, which would be the route I would investigate for filled geometries, such as the land outline (as opposed to the coastline, which is strictly an outline).
The important step is to convert the paths to polygons, and use these in a PolyCollection object:
concat = lambda iterable: list(itertools.chain.from_iterable(iterable))
polys = concat(path.to_polygons() for path in paths)
lc = PolyCollection(polys, edgecolor='black',
facecolor='green', closed=False)
The complete code for this case would look something like:
import itertools
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib.collections import LineCollection, PolyCollection
import numpy as np
import cartopy.feature
from cartopy.mpl.patch import geos_to_path
import cartopy.crs as ccrs
fig = plt.figure()
ax = Axes3D(fig, xlim=[-180, 180], ylim=[-90, 90])
ax.set_zlim(bottom=0)
concat = lambda iterable: list(itertools.chain.from_iterable(iterable))
target_projection = ccrs.PlateCarree()
feature = cartopy.feature.NaturalEarthFeature('physical', 'land', '110m')
geoms = feature.geometries()
geoms = [target_projection.project_geometry(geom, feature.crs)
for geom in geoms]
paths = concat(geos_to_path(geom) for geom in geoms)
polys = concat(path.to_polygons() for path in paths)
lc = PolyCollection(polys, edgecolor='black',
facecolor='green', closed=False)
ax.add_collection3d(lc)
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Height')
plt.show()
To yield:
Related
I have tried to write some example with keras,but some error happenError when checking target: expected dense_2 to have shape (2,) but got array with shape (1,)
I have tried to change the input_shape but it doesn't work
import keras
from keras.models import Sequential
from keras.layers import Dense
from keras.optimizers import SGD
from sklearn.preprocessing import LabelBinarizer
from sklearn.model_selection import train_test_split
import numpy
print "hello"
input=[[1],[2],[3],[4],[5],[6],[7],[8]]
input=numpy.array(input, dtype="float")
# input=input.reshape(8,1)
output=[[1],[0],[1],[0],[1],[0],[1],[0]]
output=numpy.array(output, dtype="float")
(trainx,testx,trainy,testy)=train_test_split(input, output, test_size=0.25, random_state=42)
lb = LabelBinarizer()
trainy=lb.fit_transform(trainy)
testy=lb.transform(testy)
model=Sequential()
model.add(Dense(4,input_shape=(1,),activation="sigmoid"))
# model.add(Dense(4,activation="sigmoid"))
# print len(lb.classes_)
model.add(Dense(len(lb.classes_),activation="softmax",input_shape=(4,)))
INIT_LR = 0.01
EPOCHS = 20
print("[INFO] training network...")
opt = SGD(lr=INIT_LR)
model.compile(loss="categorical_crossentropy", optimizer=opt,metrics=["accuracy"])
H = model.fit(trainx, trainy, validation_data=(testx, testy),epochs=EPOCHS, batch_size=2)
Since you have two classes, you can have a single neuron in the final Dense layer and use sigmoid activation. Or if you want to use softmax, you need to create a one hot encoding of y like this.
(trainx,testx,trainy,testy)=train_test_split(input, output, test_size=0.25, random_state=42)
trainy = keras.utils.to_categorical(trainy, 2)
testy = keras.utils.to_categorical(testy, 2)
You should use "from tensorflow.python.keras.xx" instead of "from keras.xx". It prevents it from receiving the error like: "AttributeError: module 'tensorflow' has no attribute 'get_default_graph"
I'm tying to use Keras for image recognition, but kept getting errors like:
ValueError: Error when checking input: expected input_9 to have 4 dimensions, but got array with shape (100, 300, 300)
I tried to change values for params that relate to dimensions, also tried to reshape images, but still got errors.
In fact, I don't understand why did I get this error. Why it expects 4 dimensions?
Here's my code:
import os
import numpy as np
import pandas as pd
import scipy
import sklearn
import keras
from keras.models import Sequential
from keras.layers import Dense, Activation, Dropout, Convolution2D, Flatten, MaxPooling2D, Reshape, InputLayer
import cv2
from skimage import io
import urllib2
from PIL import Image
import numpy as np
%matplotlib inline
I chose 50 rose images and 50 sunflower images from imagenet:
rose_file = "http://www.image-net.org/api/text/imagenet.synset.geturls?wnid=n04971313"
sunflower_file = "http://www.image-net.org/api/text/imagenet.synset.geturls?wnid=n11978713"
images = []
image_num = 50
rose_urls = urllib2.urlopen(rose_file)
rose_ct = 0
for rose_url in rose_urls:
try:
resp = urllib2.urlopen(rose_url)
rose_image = np.asarray(bytearray(resp.read()), dtype="uint8")
images.append(rose_image)
rose_ct += 1
if rose_ct == image_num: # only use 50 images here, otherwise, loading time is too long
break
except: # some images are no longer available
pass
sunflower_urls = urllib2.urlopen(sunflower_file)
sunflower_ct = 0
for sunflower_url in sunflower_urls:
try:
resp = urllib2.urlopen(sunflower_url)
sunflower_image = np.asarray(bytearray(resp.read()), dtype="uint8")
images.append(sunflower_image)
sunflower_ct += 1
if sunflower_ct == image_num: # only use 50 images here, otherwise, loading time is too long
break
except: # some images are no longer available
pass
Resize training images to 300*300:
from keras.utils.np_utils import to_categorical
for i in range(len(images)):
images[i]=cv2.resize(np.array(images[i]),(300,300))
images = np.array(images)
labels = [0 for i in range(image_num)]
labels.extend([1 for j in range(image_num)])
labels = np.array(labels)
labels = to_categorical(labels)
Build the model:
filters=10
filtersize=(5,5)
epochs=7
batchsize=128
input_shape=(300,300, 3)
model = Sequential()
model.add(keras.layers.InputLayer(input_shape=input_shape))
model.add(keras.layers.convolutional.Conv2D(filters, filtersize, strides=(1, 1),
padding='valid', data_format="channels_last", activation='relu'))
model.add(keras.layers.MaxPooling2D(pool_size=(2, 2)))
model.add(keras.layers.Flatten())
model.add(keras.layers.Dense(units=2, input_dim=10, activation='softmax'))
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
model.fit(images, labels, epochs=epochs, batch_size=batchsize, validation_split=0.3)
model.summary()
Here, I tried to change input_shape=(300,300, 3) into input_shape=(300,300, 3, 0), hoping this means 4 dimensions, but got errors saying:
Input 0 is incompatible with layer conv2d_13: expected ndim=4, found ndim=5
Do you know why did I get these errors? And how to deal with this problem?
Is there a way to change the axis' format on a tkinter graph? As you can see I use a plot widget to put my graphs on my frame. Is there a way for me to make the dates on the bottom in num/num format? Like 4/18 rather than April 18 2017? Heres my code: (Also is it possible to change color of my graph backgrounds? They are defaulted to gray)
import numpy as np
import datetime as dt
import yahoo_finance as yf
import matplotlib.pyplot as plt
from Tkinter import *
import quandl
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
root=Tk()
root.geometry('1400x875')
root.title("Stock Information")
fmain=Frame(root, width=1400, height=900)
fmain.place(x=100, y=0)
today=dt.date.today()
thirty_day_graph_frame=Frame(fmain, width=1290, height=300)
thirty_day_graph_frame.place(x=0, y=240)
thirty_days=dt.timedelta(days=43)
thirty_days_ago=today-thirty_days
five_yrs_graph_frame=Frame(fmain, width=1290, height=300)
five_yrs_graph_frame.place(x=0, y=540)
five_years=dt.timedelta(days=1825)
five_years_ago=today-five_years
def stock_info(stock_name):
global five_yrs_graph_frame
five_yrs_graph_frame.destroy()
global thirty_day_graph_frame
thirty_day_graph_frame.destroy()
thirty_day_graph_frame=Frame(fmain, width=1290, height=300)
thirty_day_graph_frame.place(x=0, y=240)
five_yrs_graph_frame=Frame(fmain, width=1290, height=300)
five_yrs_graph_frame.place(x=0, y=540)
stock=yf.Share(stock_name)
stock_price=stock.get_price()
name_price_label=Label(fmain, text=(stock_name,':', stock_price),font=("Times New Roman",23))
name_price_label.place(x=400, y=10)
day_change=stock.get_change()
if float(day_change) > 0:
font_color="green"
elif float(day_change) < 0:
font_color="red"
else:
font_color="yellow"
day_change_label=Label(fmain, text=(day_change),font=("Times New Roman",20),fg=str(font_color))
day_change_label.place(x=400, y=40)
thirty_day_data = quandl.get("WIKI/"+str(stock_name), start_date=str(thirty_days_ago), end_date=str(today),column_index=4) #So quandl.get gives a lot of info, so the column_index=4 is just getting closing prices
five_year_data = quandl.get("WIKI/"+str(stock_name),start_date=str(five_years_ago), end_date=str(today), column_index=4)
thirty_day_fig = plt.figure(figsize=(10,3.75))
plt.plot(thirty_day_data)
canvas = FigureCanvasTkAgg(thirty_day_fig, master=thirty_day_graph_frame)
plot_widget = canvas.get_tk_widget()
plot_widget.place(x=0,y=0)
five_year_fig=plt.figure(figsize=(10,3.75))
plt.plot(five_year_data)
canvas1=FigureCanvasTkAgg(five_year_fig, master=five_yrs_graph_frame)
plot_widget1=canvas1.get_tk_widget()
plot_widget1.place(x=1,y=0)
apple_button=Button(root,text='AAPL', command=lambda:stock_info('AAPL'))
tesla_button=Button(root,text='TSLA', command=lambda:stock_info('TSLA'))
google_button=Button(root,text='GOOG', command=lambda:stock_info('GOOG'))
apple_button.place(x=10, y=15)
tesla_button.place(x=10, y=45)
google_button.place(x=10,y=75)
root.mainloop()
You can use the datetime library with using the function strftime
from datetime import datetime
today = datetime.today()
print ('ISO :', today) # ISO: 2017-05-25 16:23:35.850570
format = "%d/%m"
s = today.strftime(format)
print (s) # 25/05
You can read more about this function and formats options in here
I am struggling to have construct an interactive tool in jupyter notebook. Based on the discussion here : IPython Notebook widgets for Matplotlib interactivity, I've build the following example:
%matplotlib notebook
import matplotlib.pyplot as plt
from ipywidgets import Select,interactive,Dropdown
from IPython.display import display
fig,ax = plt.subplots()
ax.plot(range(5))
vline = ax.axvline(1, color='k')
hline = ax.axhline(0.5, color='k')
def set_cursor(x, y):
vline.set_xdata((x, x))
hline.set_ydata((y, y))
ax.figure.canvas.draw_idle()
interactive(set_cursor, x=ax.get_xlim(), y=ax.get_ylim())
It works pretty well except that that the last line (interactive...) has to be run in a different cell.
If I want to launch everything in the same cell (or from the same object if use a Class approach, which is what I want at the end), I have to use the following code:
%matplotlib notebook
import matplotlib.pyplot as plt
from ipywidgets import Select,interactive,Dropdown
from IPython.display import display
fig,ax = plt.subplots()
ax.plot(range(5))
vline = ax.axvline(1, color='k')
hline = ax.axhline(0.5, color='k')
def set_cursor(x, y):
vline.set_xdata((x, x))
hline.set_ydata((y, y))
ax.figure.canvas.draw_idle()
display(fig)
tool = interactive(set_cursor, x=ax.get_xlim(), y=ax.get_ylim())
display(tool)
But in this case, the complete figure is redraw each time a new value is selected in a widget
Is there any possibility to get everything launch smoothly from the same cell ?
Any idea is more than welcome !
Is it possible to integrate any Ordinary Differential Equation backward in time
using scipy.integrate.odeint ?
If it is possible, could someone tell me what should be the arguement 'time' in 'odeint.
odeint handles negative values of the t argument. No special treatment is needed.
Here's an example:
import numpy as np
from scipy.integrate import odeint
import matplotlib.pyplot as plt
def mysys(z, t):
"""A slightly damped oscillator."""
return [z[1] - 0.02*z[0], -z[0]]
if __name__ == "__main__":
# Note that t starts at 0 and goes "backwards"
t = np.linspace(0, -50, 501)
z0 = [1, 1]
sol = odeint(mysys, z0, t)
plt.plot(t, sol)
plt.xlabel('t')
plt.show()
The plot:
You can make a change of variables s = t_0 - t, and integrate the differential equation with respect to s. odeint doesn't do this for you.
It is not necessary to make a change of variables. Here an example:
import math
import numpy
import scipy
import pylab as p
from math import *
from numpy import *
from scipy.integrate import odeint
from scipy.interpolate import splrep
from scipy.interpolate import splev
g1=0.01
g2=0.01
w1=1
w2=1
b1=1.0/20.0
b2=1.0/20.0
b=1.0/20.0
c0=0
c1=0.2
wf=1
def wtime(t):
f=1+c0+c1*cos(2*wf*t)
return f
def dv(y,t):
return array([y[1], -(wtime(t)+g1*w1+g2*w2)*y[0]+w1*y[2]+w2*y[3], w1*y[2]-g1*w1*y[0], w2*y[3]-g2*w2*y[0]])
tv=linspace(100,0,1000)
v1zero=array([1,0,0,0])
v2zero=array([0,1,0,0])
v1s=odeint(dv,v1zero,tv)
v2s=odeint(dv,v2zero,tv)
p.plot(tv,v1s[:,0])
p.show()
I check the result with Wolfram Mathematica (that program can solve backward odes).