visbrain.objects.ConnectObj¶

class visbrain.objects.ConnectObj(name, nodes, edges, select=None, line_width=3.0, color_by='strength', custom_colors=None, alpha=1.0, antialias=False, dynamic=None, dynamic_order=1, dynamic_orientation='ascending', cmap='viridis', clim=None, vmin=None, vmax=None, under='gray', over='red', transform=None, parent=None, verbose=None, _z=-10.0, **kw)[source][source]¶

Create a connectivity object.

Parameters

namestring

The name of the connectivity object.

nodesarray_like

Array of nodes coordinates of shape (n_nodes, 3).

edgesarray_like | None

Array of ponderations for edges of shape (n_nodes, n_nodes).

selectarray_like | None

Array to select edges to display. This should be an array of boolean values of shape (n_nodes, n_nodes).

line_widthfloat | 3.

Connectivity line width.

color_by{‘strength’, ‘count’, ‘causal’}

Coloring method:

‘strength’ : color edges according to their connection strength define by the edges input. Only the upper triangle of the connectivity array is considered.

‘count’ : color edges according to the number of connections per node. Only the upper triangle of the connectivity array is considered.

‘causal’ : color edges according to the connectivity strength but this time, the upper and lower triangles of the connectivity array in edges are considered.

custom_colorsdict | None

Use a dictionary to colorize edges. For example, {1.2: ‘red’, 2.8: ‘green’, None: ‘black’} turn connections that have a 1.2 and 2.8 strength into red and green. All others connections are set to black.

alphafloat | 1.

Transparency level (if dynamic is None).

antialiasbool | False

Use smoothed lines.

dynamictuple | None

Control the dynamic opacity. For example, if dynamic=(0, 1), strong connections will be more opaque than weaker connections.

dynamic_orderint | 1

If 1, the dynamic transparency is linearly modulated by the connectivity. If 2, the transparency follow a x**2 curve etc.

dynamic_orientationstr | ‘ascending’

Define the transparency behavior :

‘ascending’ : from translucent to opaque

‘center’ : from opaque to translucent and finish by opaque

‘descending’ ; from opaque to translucent

cmapstring | ‘viridis’

Colormap to use if custom_colors is None.

vminfloat | None

Lower threshold of the colormap if custom_colors is None.

understring | None

Color to use for values under vmin if custom_colors is None.

vminfloat | None

Higher threshold of the colormap if custom_colors is None.

overstring | None

Color to use for values over vmax if custom_colors is None.

transformVisPy.visuals.transforms | None

VisPy transformation to set to the parent node.

parentVisPy.parent | None

Line object parent.

verbosestring

Verbosity level.

_zfloat | 10.

In case of (n_sources, 2) use _z to specify the elevation.

kwdict | {}

Optional arguments are used to control the colorbar (See ColorbarObj).

Notes

List of supported shortcuts :

s : save the figure

<delete> : reset camera

Examples

>>> import numpy as np
>>> from visbrain.objects import ConnectObj
>>> n_nodes = 100
>>> nodes = np.random.rand(n_nodes, 3)
>>> edges = np.random.uniform(low=-10., high=10., size=(n_nodes, n_nodes))
>>> select = np.logical_and(edges >= 0, edges <= 1.)
>>> c = ConnectObj('Connect', nodes, edges, select=select, cmap='inferno',
>>>                antialias=True)
>>> c.preview(axis=True)

Methods

`__init__`(self, name, nodes, edges[, select, …])	Init.
`analyse_connections`(self[, roi_obj, …])	Analyse connections.
`animate`(self[, step, interval, iterations])	Animate the object.
`copy`(self)	Get a copy of the object.
`describe_tree`(self)	Tree description.
`get_nb_connections_per_node`(self[, sort, order])	Get the number of connections per node.
`preview`(self[, bgcolor, axis, xyz, show, …])	Previsualize the result.
`record_animation`(self, name[, n_pic, bgcolor])	Record an animated object and save as a *.gif file.
`render`(self)	Render the canvas.
`screenshot`(self, saveas[, print_size, dpi, …])	Take a screeshot of the scene.
`set_shortcuts_to_canvas`(self, canvas)	Set shortcuts to a VisbrainCanvas.
`to_dict`(self)	Return a dictionary of all colorbar args.
`to_kwargs`(self[, addisminmax])	Return a dictionary for input arguments.
`update`(self)	Update the line.
`update_from_dict`(self, kwargs)	Update attributes from a dictionary.

alpha¶: Get the alpha value.

analyse_connections(self, roi_obj='talairach', group_by=None, get_centroids=False, replace_bad=True, bad_patterns=[-1, 'undefined', 'None'], distance=None, replace_with='Not found', keep_only=None)[source][source]¶

Analyse connections.

Parameters

roi_objstring/list | ‘talairach’: The ROI object to use. Use either ‘talairach’, ‘brodmann’ or ‘aal’ to use a predefined ROI template. Otherwise, use a RoiObj object or a list of RoiObj.
group_bystr | None: Name of the column inside the dataframe for gouping connectivity results.
replace_badbool | True: Replace bad values (True) or not (False).
bad_patternslist | [-1, ‘undefined’, ‘None’]: Bad patterns to replace if replace_bad is True.
replace_withstring | ‘Not found’: Replace bad patterns with this string.
keep_onlylist | None: List of string patterns to keep only sources that match.

Returns

dfpandas.DataFrames: A Pandas DataFrame or a list of DataFrames if roi_obj is a list.

animate(self, step=1.0, interval='auto', iterations=-1)[source]¶

Animate the object.

Note that this method can only be used with 3D objects.

Parameters

stepfloat | 1.: Rotation step.
intervalfloat | ‘auto’: Time between events in seconds. The default is ‘auto’, which attempts to find the interval that matches the refresh rate of the current monitor. Currently this is simply 1/60.
iterationsint | -1: Number of iterations. Can be -1 for infinite.

cmap¶: Get the cmap value.

color_by¶: Get the color_by value.

copy(self)[source]¶: Get a copy of the object.

data_folder¶: Get the data_folder value.

dynamic¶: Get the dynamic value.

get_nb_connections_per_node(self, sort='index', order='ascending')[source][source]¶

Get the number of connections per node.

Parameters

sort{‘index’, ‘count’}: Sort either by node index (‘index’) or according to the number of connections per node (‘count’).
order{‘ascending’, ‘descending’}: Get the number of connections per node

line_width¶: Get the line_width value.

name¶: Get the name value.

parent¶: Get the parent value.

preview(self, bgcolor='black', axis=False, xyz=False, show=True, obj=None, size=(1200, 800), mpl=False, **kwargs)[source]¶

Previsualize the result.

Parameters

bgcolorarray_like/string/tuple | ‘black’: Background color for the preview.
axisbool | False: Add x and y axis with ticks.
xyzbool | False: Add an (x, y, z) axis to the scene.
objVisbrainObj | None: Pass a Visbrain object if you want to use the camera of an other object.
sizetuple | (1200, 800): Default size of the window.
mplbool | False: Use Matplotlib to display the object. This result in a non interactive figure.
kwargsdict | {}: Optional arguments are passed to the VisbrainCanvas class.

record_animation(self, name, n_pic=10, bgcolor=None)[source]¶

Record an animated object and save as a *.gif file.

Note that this method :

Can only be used with 3D objects.

Requires the python package imageio

Parameters

namestring: Name of the gif file (e.g ‘myfile.gif’)
n_picint | 10: Number of pictures to use to render the gif.
bgcolorstring, tuple, list | None: Background color.

render(self)[source]¶

Render the canvas.

Returns

imgarray_like: Array of shape (n_rows, n_columns, 4) where 4 describes the RGBA components.

screenshot(self, saveas, print_size=None, dpi=300.0, unit='centimeter', factor=None, region=None, autocrop=False, bgcolor=None, transparent=False, obj=None, line_width=1.0, **kwargs)[source]¶

Take a screeshot of the scene.

By default, the rendered canvas will have the size of your screen. The screenshot() method provides two ways to increase to exported image resolution :

Using print_size, unit and dpi inputs : specify the size of the image at a specific dpi level. For example, you might want to have an (10cm, 15cm) image at 300 dpi.

Using the factor input : multiply the default image size by this factor. For example, if you have a (1920, 1080) monitor and if factor is 2, the exported image should have a shape of (3840, 2160) pixels.

Parameters

saveasstr: The name of the file to be saved. This file must contains a extension like .png, .tiff, .jpg…
print_sizetuple | None: The desired print size. This argument should be used in association with the dpi and unit inputs. print_size describe should be a tuple of two floats describing (width, height) of the exported image for a specific dpi level. The final image might not have the exact desired size but will try instead to find a compromize regarding to the proportion of width/height of the original image.
dpifloat | 300.: Dots per inch for printing the image.
unit{‘centimeter’, ‘millimeter’, ‘pixel’, ‘inch’}: Unit of the printed size.
factorfloat | None: If you don’t want to use the print_size input, factor simply multiply the resolution of your screen.
regiontuple | None: Select a specific region. Must be a tuple of four integers each one describing (x_start, y_start, width, height).
autocropbool | False: Automaticaly crop the figure in order to have the smallest space between the brain and the border of the picture.
bgcolorarray_like/string | None: The background color of the image.
transparentbool | False: Specify if the exported figure have to contains a transparent background.
objVisbrainObj | None: Pass a Visbrain object if you want to use the camera of an other object for the sceen rendering.
kwargsdict | {}: Optional arguments are passed to the VisbrainCanvas class.

transform¶: Get the transform value.

visible_obj¶: Get the visible_obj value.

Examples using `visbrain.objects.ConnectObj`¶

Animate objects in the scene¶

Combine multiple objects¶

Connectivity object (ConnectObj) : complete tutorial¶

Connect deep sources¶

Add multiple objects to the scene¶

visbrain.objects.ConnectObj¶

Examples using visbrain.objects.ConnectObj¶

Examples using `visbrain.objects.ConnectObj`¶