Vertex

class feynman.Vertex(xy=(0, 0), **kwargs)

A vertex. Usually represented as a disc.

Parameters:

• xy ([x, y]) – Coordinates of the vertex.
• dxy – Coordinates shift, so that the position is given by xy + dxy.
• dx – Coordinates shift in the x direction.
• dy – Coordinates shift in the y direction.
• angle – Angle from xy, so that the position is given by xy + radius * [cos(angle), sin(angle)]. Angle is given in units of tau=2pi.
• radius – Radius from xy, so that the position is given by xy + radius * [cos(angle), sin(angle)].
• **kwargs – Any matplotlib line style argument.

scale(x)

Apply a scaling factor to the size of the marker.

set_xy(xy)

Set the position of the vertex.

style

A dictionary of matplotlib line style, such as marker, markersize, color, etc.

text(s, x=-0.025, y=0.025, **kwargs)

Add text near the vertex.

Parameters:

• s (Text string.) –
• x ((-0.025)) – x position, relative to the vertex.
• y ((-0.025)) – y position, relative to the vertex.
• fontsize – The font size.
• **kwargs – Any other style specification for a matplotlib.text.Text instance.