# coding: utf-8

# # <img style='float: left' src="http://lightning-viz.github.io/images/logo.png"> <br> <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Brushing in <a href='http://lightning-viz.github.io/'><font color='#9175f0'>Lightning</font></a>

# ## <hr> Setup

# In[1]:


from lightning import Lightning

from numpy import random, zeros


# ## Connect to server

# In[2]:


lgn = Lightning(ipython=True, host='http://public.lightning-viz.org')


# ## <hr> Adding brushing

# Several visualizations support brushing, including graphs, force networks, and scatter plots. Just set `brush=True`, then SHIFT-click and drag to select points. You should see them highlighted as you drag. We'll also turn off zooming for these examples, which can simplify our interactions with the plot.

# In[3]:


x = random.randn(100)
y = random.randn(100)

lgn.scatter(x, y, brush=True, zoom=False)


# ## <hr> Getting selections

# If working with a Lightning server (rather than the server-less mode), we can easily extract the points we've selected. 

# In[4]:


x = random.rand(100) * 10
y = random.rand(100) * 10

viz = lgn.scatter(x, y, brush=True, zoom=False)
viz


# Let's say I use the brush in the visualization above to select all points between 0 and 4. Below, I grab those points, and replot them -- note the new scale.

# In[5]:


sx, sy = viz.points()


# In[6]:


lgn.scatter(sx, sy, zoom=False)


# I can use a different accessor, `selected`, to grab the indices of the selected points.

# In[7]:


inds = viz.selected()


# Let's replot all points, but show the selected ones in a different color.

# In[8]:


groups = zeros(100)
groups[inds] = 1

lgn.scatter(x, y, group=groups, zoom=False)