#!/usr/bin/env python
# coding: utf-8

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# <br>We also have a quick-reference [cheatsheet](https://images.plot.ly/plotly-documentation/images/python_cheat_sheet.pdf) (new!) to help you get started!
# #### Version Check
# Plotly's python API is updated frequesntly. Run pip install plotly --upgrade to update your Plotly version.

# In[1]:


import plotly
plotly.__version__


# #### Basic Quiver Plot

# In[2]:


import plotly.plotly as py
import plotly.figure_factory as ff

import numpy as np

x,y = np.meshgrid(np.arange(0, 2, .2), np.arange(0, 2, .2))
u = np.cos(x)*y
v = np.sin(x)*y

fig = ff.create_quiver(x, y, u, v)
py.iplot(fig, filename='Quiver Plot Example')


# #### Quiver Plot with Points

# In[3]:


import plotly.plotly as py
import plotly.figure_factory as ff
import plotly.graph_objs as go

import numpy as np

x,y = np.meshgrid(np.arange(-2, 2, .2),
                  np.arange(-2, 2, .25))
z = x*np.exp(-x**2 - y**2)
v, u = np.gradient(z, .2, .2)

# Create quiver figure
fig = ff.create_quiver(x, y, u, v,
                       scale=.25,
                       arrow_scale=.4,
                       name='quiver',
                       line=dict(width=1))

# Create points
points = go.Scatter(x=[-.7, .75], y=[0,0],
                    mode='markers',
                    marker=dict(size=12),
                    name='points')

# Add points to figure
fig['data'].append(points)

py.iplot(fig, filename='Quiver with Points')


# #### Reference 

# In[4]:


help(ff.create_quiver)


# In[5]:


from IPython.display import display, HTML

display(HTML('<link href="//fonts.googleapis.com/css?family=Open+Sans:600,400,300,200|Inconsolata|Ubuntu+Mono:400,700" rel="stylesheet" type="text/css" />'))
display(HTML('<link rel="stylesheet" type="text/css" href="http://help.plot.ly/documentation/all_static/css/ipython-notebook-custom.css">'))

get_ipython().system(' pip install git+https://github.com/plotly/publisher.git --upgrade')
import publisher
publisher.publish(
    'quiver.ipynb', 'python/quiver-plots/', 'Python Quiver Plots | plotly',
    'How to make a quiver plot in Python. A quiver plot displays velocity vectors a arrows. ',
    title = 'Python Quiver Plots | plotly',
    name = 'Quiver Plots',
    has_thumbnail='true', thumbnail='thumbnail/quiver-plot.jpg', 
    language='python', 
    display_as='scientific', order=12,
    ipynb= '~notebook_demo/42')  


# In[ ]: