cpsmehelper 1.0.1

Helper functions of the CPSME TU Berlin

CPSME Chair

This Python library was developed by the Chair of Cyber-Physical Systems in Mechanical Engineering at the TU Berlin. The Chair is led by Prof. Merten Stender and was founded January 2023. The Chair's research focuses on Digital Twins, Dynamics and Artificial Intelligence, and Hybrid Simulation.

This library provides tools to create standardized visual representations and plots according to the Chair's design guidelines. The two key functions for this are the following:

• Export Figure Function for consistent figure export
• Get Colors Function for unified color schemes

Export Figure Function

The CPSME has developed a function enabling users to effortlessly export Python matplotlib figures to .png, .svg, .pdf, and .tikz files. This function is called export_figure().

def export_figure(fig, 
                  name: str, 
                  savedir: str = None, 
                  style: str = None, 
                  width: float = None, 
                  height: float = None, 
                  resolution: int = 300)

Users can customize several parameters according to their preferences, which then will be reflected in the exported file. A quick explanation of the parameters, peculiarities, as well as a minimal working example of how to use the function can be found below.

Parameters

fig

Needs to be set to the plt figure object, that is to be exported.

name

Sets the file name and needs to include the desired file ending.

savedir

Sets the directory, where the file is saved. The default is set to the current working directory.

style

Several predefined styles can be set. Those styles determine the width and height of the exported file.
For presentations, based on the CPSME guidelines:

• presentation_1x1 indicates a full PowerPoint textbox
• presentation_1x2 indicates a PowerPoint textbox split into halves in width
• presentation_1x3 indicates a PowerPoint textbox split into thirds in width
• presentation_2x1 indicates a PowerPoint textbox split into halves in height
• presentation_2x2 indicates a PowerPoint textbox split into halves in height and halves in width
• presentation_2x3 indicates a PowerPoint textbox split into halves in height and thirds in width

width

Sets the exported file to an individually set width. Over-writes the style argument.

height

Sets the exported file to an individually set height. Over-writes the style argument.

resolution

Sets the resolution of the .png file. The default DPI is set to 300.

Peculiarities

• for plots with equal axes the input for the width is favored
• small offsets can happen randomly
• when exporting .tikz files the compatibility of Matplotlib and the library used for exporting the .tikz file needs to be accounted for; more detailed information can be found in the Exporting .tikz files from Python Matplotlib entry

Minimal Working Example

import numpy as np
from matplotlib import pyplot as plt

# import export_figure function from cpsmehelper library
from cpsmehelper import export_figure

# create plot 
data = np.random.randn(10)
fig, ax = plt.subplots()
ax.plot(data, data)
ax.plot(data, -data)
plt.xlabel('xlabel')
plt.ylabel('ylabel')
plt.legend(['some data', 'different data'])

# export figure to a .svg file with a set presentation style of one full PP textbox
export_figure(fig, name='test_presentation_1x1.svg', style='presentation_1x1')

Get Colors Function

The CPSME has a set of 'official' colors used for visualizations. The get_colors() function can be used to load a dict of the color set.

def get_colors(format: str = 'hash')

Users can set the format of the values returned in the dict or load specific colors. The function's format parameter, available colors, as well as a minimal working example can be found below.

Parameters

format

The format of the color values returned in the dict can be specified. The default is set to the hash value, which can be freely used in matplotlib.
The possible return formats are the following:

• 'hash' returns the hash value of the colors
• 'rgb_perc' returns the RGB percentage value of the colors
• 'rgb_dec' returns the RGB decimal value of the colors

The following table shows the official' CPSME colors. The gradation of colors from 1 to 4 indicates a gradient from light to dark. The colors of the dict are called according to the 'variable' parameter in the table. How to call and use a specific color is shown in the minimal working example.

variable	rgb (decimal)	RGB (percentage)	# hash
black	50, 50, 50	19.6, 19.6, 19.6	#323232
white	250, 250, 250	98, 98, 98	#FAFAFA
blue_4	29, 53, 87	11.4, 20.8, 34.1	#1D3557
red	230, 57, 70	90.2, 22.4, 27.5	#E63946
green	0, 182, 149	0, 71.4, 58.4	#00b695
blue_2	0, 139, 154	0, 54.5, 60.4	#008b9a
blue_3	69, 123, 157	27.1, 48.2, 61.6	#457B9D
blue_1	168, 218, 220	65.9, 85.5, 86.3	#A8DADC
grey_4	100, 100, 100	39.2, 39.2, 39.2	#646464
grey_1	225, 225, 225	88.2, 88.2, 88.2	#E1E1E1
grey_2	200, 200, 200	78.4, 78.4, 78.4	#C8C8C8
grey_3	150, 150, 150	58.8, 58.8, 58.8	#969696
mint_green	241, 250, 238	94.5, 98, 93.3	#F1FAEE

Minimal Working example

import matplotlib.pyplot as plt
import numpy as np

# import cpsme color dict 
from cpsmehelper import get_colors

# get entire color dict in hash values
cpsme_colors = get_colors()

# get one specific color in hash value
cpsme_red = get_colors()['red']

# generate data
x = np.linspace(0, 10, 100)  # 100 points from 0 to 10
y_1 = np.sin(x)                # sine function
y_2 = y_1 * 2

# create the plot
plt.figure(figsize=(8, 5))
plt.plot(x, y_1, label='Sine Wave ', color=cpsme_colors['blue_4'], linestyle='-', marker='o')  # use cpsme blue 4 for plot
plt.plot(x, y_2, label='Sine Wave * 2', color=cpsme_red, linestyle='-', marker='o')  # use cpsme red for plot

# add labels and title
plt.xlabel('X-axis')
plt.ylabel('Y-axis')
plt.title('Simple Sine Wave Plot')
plt.grid(True)
plt.legend()

# show the plot
plt.show()