Draw a 2D representation of an object#
PlotData allows to draw complex shapes and to associate them with a DessiaObject.
Available shapes#
The following bullet point lists all available shapes in PlotData and how to instantiate and draw them. For the sake of simplicity, imports are given just below and used for all the following shapes.
import math
import plot_data as pld
from plot_data.colors import ORANGE, BLACK, BLUE, LIGHTGREEN
Point: draw a point at the given 2D coordinates (cx, cy). To create a Point2D which drawing parameters are customized, write the following lines:
point_style = pld.PointStyle(
color_fill=ORANGE,
color_stroke=BLACK,
stroke_width=2,
shape="circle",
size = 20
)
point = pld.Point2D(
cx = 1,
cy=12,
point_style=point_style,
tooltip="Circle point"
)
Line segment: draw a line segment between two given points. To create a LineSegment2D which drawing parameters are customized, write the following lines:
edge_style = pld.EdgeStyle(
line_width=3,
color_stroke=BLUE,
dashline=[5, 2]
)
line_segment = pld.LineSegment2D(
point1=[0, 0],
point2=[20, 16],
edge_style=edge_style,
tooltip="LineSegment2D"
)
Line: draw an infinite line crossing two given points. To create a Line2D (same style customization as LineSegment2D) write the following lines:
pld.Line2D(
point1=[-10, 24.5],
point2=[22, 24.5],
edge_style=edge_style,
tooltip="Line2D"
)
Rectangle: draw a rectangle with given origin coordinates, width and height. To create a Rectangle which drawing parameters are customized, write the following lines:
# Surface hatching
hatching = pld.HatchingSet(1, 10)
surface_style = pld.SurfaceStyle(
color_fill=LIGHTGREEN,
opacity=0.8,
hatching=hatching
)
edge_style = pld.EdgeStyle(
line_width=3,
color_stroke=BLUE,
dashline=[5, 2]
)
rectangle = pld.Rectangle(
x_coord=-6, y_coord=16, width=15, height=10,
surface_style=surface_style,
edge_style=edge_style,
tooltip="rectangle"
)
Round rectangle: draw a rectangle with given origin coordinates, width, height and radius. To create a RoundRectangle`(same style customization as `Rectangle) write the following lines:
round_rect = pld.RoundRectangle(
x_coord=24, y_coord=0, width=60, height=37, radius=1,
edge_style=edge_style,
surface_style=surface_style,
tooltip="round_rectangle"
)
Circle: draw a circle with given origin coordinates and radius. To create a Circle (same style customization as Rectangle) write the following lines:
circle = pld.Circle2D(
cx=15,
cy=35,
r=5,
edge_style=edge_style,
surface_style=surface_style,
tooltip="Circle"
)
Arc: draw an arc with given origin coordinates, radius and start and end angles. To create an Arc2D (same style customization as Line) write the following lines:
arc = pld.Arc2D(
cx=0,
cy=30,
r=5,
start_angle=math.pi/4,
end_angle=2*math.pi/3,
edge_style=edge_style,
clockwise=False, # Specify the turning sense for drawing the arc
tooltip="arc_anticlockwise"
)
Wire: draw a 2D polygon connecting the given points. It can be closed or open. To create a Wire (same customization as Line) write the following lines:
# Point series ([x1, y1],...,[xn, yn]) to link with lines
lines = [
[25, 35], [28, 26], [29, 30], [30, 26],
[33, 35], [34, 35], [34, 26], [35, 26],
[35, 35], [40, 35], [35, 30], [40, 26],
[44, 26], [41, 26], [41, 30.5], [43, 30.5],
[41, 30.5], [41, 35], [44, 35]
]
wire = pld.Wire(
lines=lines,
tooltip="Wire",
edge_style=edge_style
)
Contour: draw a 2D polygon with arcs and lines. It can be closed or open. To get a transparent filling for the Contour, do not specify any SurfaceStyle when building it. To create a Contour (same style customization as Rectangle) write the following lines:
heart_lines = [
pld.LineSegment2D([51, 26], [47, 33]),
pld.Arc2D(cx=49, cy=33, r=2, start_angle=math.pi, end_angle=0, clockwise=True),
pld.Arc2D(cx=53, cy=33, r=2, start_angle=math.pi, end_angle=0, clockwise=True),
pld.LineSegment2D([55, 33], [51, 26])
]
contour = pld.Contour2D(
plot_data_primitives=heart_lines,
edge_style=pld.EdgeStyle(line_width=2, color_stroke=BORDEAUX),
surface_style=pld.SurfaceStyle(color_fill=RED),
tooltip="Heart shaped contour.")
Text: write text at the specified coordinates with the given text properties. To create a Text write the following lines and specify the following attribute for it to fit with its requirements:
text_style attribute allows to specify a `TextStyle`to custom text font, size and align
text_scaling attribute allows to scale the text with mouse wheel or not
max_width attribute allows to resize the text’s font automatically to be smaller than the specified length
height attribute allows to resize the text’s font automatically to be smaller than the specified height
multi_lines attribute allows to specify if the text shall automatically create a new line when it is longer than the specified max_width
# Unscaled text
unscaled = pld.Text(
comment='This text never changes its size because text_scaling is False.',
position_x=-14,
position_y=28,
text_scaling=False,
multi_lines=True
text_style=pld.TextStyle(
font_size=16,
text_align_y="top"
)
)
# Scaled text
scaled = pld.Text(
comment='Dessia',
position_x=70,
position_y=35,
text_scaling=True,
multi_lines=False,
text_style=pld.TextStyle(
font_size=8,
text_color=BLUE,
text_align_x="right",
text_align_y="bottom",
bold=True
)
)
Label: draw a label with the given text or for the given shape. To create a Label create a shape and associate it to a Label or write a text and set a style to show anything else. The following lines give the procedure to build labels:
# Standalone Label
text_style = pld.TextStyle(
text_color=ORANGE,
font_size=14,
italic=True,
bold=True
)
edge_style = pld.EdgeStyle(
line_width=1,
color_stroke=BLUE,
dashline=[5, 5]
)
label_1 = pld.Label(
title='Standalone Label 1',
text_style=text_style,
rectangle_surface_style=surface_style,
rectangle_edge_style=edge_style)
# Automatic labels
## Set a shape list
shapes = [
point, line_segment, line, rectangle, round_rectangle, circle,
arc, wire, contour]
## Create a label for each shape
labels = [
pld.Label(title=type(shape).__name__, shape=shape) for shape in shapes
]
Drawing shapes in a Figure#
The previously presented shapes can all be drawn in a PrimitiveGroup (soon renamed as Draw). To do it, store all these shapes in a list and draw a PrimitiveGroup :
primitives=[point, line_segment, line, rectangle, round_rectangle,
circle, arc, wire, contour, unscaled, scaled, label_1] + labels
draw = pld.PrimitiveGroup(primitives=primitives)
Once done, the figure can be displayed with the following command line:
pld.plot_canvas(plot_data_object=draw, filepath="section2_6_2_draw")
How to add a 2D representation to a DessiaObject ?#
For the previously designed Pendulum ([section 2.1.2](https://www.notion.so/Using-data-display-with-PlotData-30f86e58db6240788cf4f3b543b0ae51?pvs=21)), an interesting 2D representation may be to represent the pendulum with its course over x and y coordinates.
To do it, add a method to build the 2D representation to the Pendulum class:
class Pendulum(DessiaObject):
:
:
:
@plot_data_view("2d_drawing")
def draw(self, reference_path: str = "#"):
# Pendulum's pivot
origin = pld.Point2D(0, 3.1, pld.PointStyle(color_fill=BLACK, color_stroke=BLACK, size=20, shape="circle"))
# Pendulum's mass object
mass_origin = [
self.length * math.sin(self.init_angle),
origin.cy - self.length *math.cos(self.init_angle)
]
mass_circle = pld.Circle2D(
cx=mass_origin[0], cy=mass_origin[1], r=0.25,
surface_style = pld.SurfaceStyle(color_fill=BLUE)
)
# Pendulum's link
bar = pld.LineSegment2D(
[origin.cx, origin.cy], mass_origin,
edge_style=pld.EdgeStyle(line_width=5, color_stroke=BLACK))
# Pendulum's course
shifted_coords = (npy.array(self.coords) + npy.array([[0, origin.cy - self.length]])).tolist()
course = pld.Wire(shifted_coords, edge_style=pld.EdgeStyle(line_width=1, color_stroke=BLUE, dashline=[7,3]))
return pld.PrimitiveGroup([origin, mass_circle, bar, course])
Once done, the figure can be displayed with the following command line:
pld.plot_canvas(plot_data_object=pendulum.draw(), canvas_id='my_draw', filepath="section2_6_3_draw")