September 3, 2021 visual notes

Calm and fearless , Brave and persistent . 

---

When implementing a data visualization, you should pay attention to ：

 " Why collect data ？ What's interesting ？ What stories can data tell ？"

For data , Need to be adequate Understand the data . secondly , Visualization is Task driven , Data visualization is a tool , The goal is to serve people . When you show it , The information conveyed by the data needs to be accurately displayed .

The visual process can be simplified to ： obtain -- analysis -- Filter -- mining -- describe -- modification -- Interaction .

Basic concepts

Scientific visualization （Scientific Visualization）、 Information visualization （Information Visualization） And visual analysis （Visual Analytics） The three disciplines are often seen as the three main branches of Visualization . These three branches are integrated to form a new discipline “ Data visualization ”, Is a new starting point in the field of visualization .——《 Data visualization 》

1. Scientific visualization scientific visualization

  Data processing + Graph drawing .

 2. Information visualization Information visualization

There are two main forms of information visualization ： Visualization attempts and visualization systems . 

 

 3. Visual analysis  Visual Analytics

data -->① Interactive visualization methods ② Automatic data mining method --> knowledge  

 ※ Core competencies include ：1- Data representation and transformation 2- Data visualization 3- User interaction

· The input data needs to be converted into a format convenient for the computer to process .

· Choose the right encoding method from a large number of rendering methods .

  Visual design

  Visual design can be simplified into four levels as shown in the figure . There is no strict order of the four levels .

  among , The third layer is the core of the design .

data

Common data classification ：

1. Category data ： A class of objects .

2. Ordered data ： Represents the order relationship between objects . There is no way to compare relative differences quantitatively .

3. Interval data ： Get a quantitative comparison between objects . Be careful ： There are only relative differences , There is no absolute difference .

4. Ratio data ： Proportional relationship between values .

Different data types --> Different operators , Different set operations , Different statistical calculations ……

Basic chart

（ Basic visual charts ）.

1 Raw data mapping . Process raw data graph . Including histogram, pie chart, histogram and scatter chart ……

2 Simple statistical plotting . Box picture https://baike.baidu.com/item/%E7%9B%92%E5%BD%A2%E5%9B%BE/2258542.

3 Multi view Coordination Association . Multi view Coordination Association combines different types of drawings , Each drawing unit can show the properties of some aspect of data , And usually allows users to conduct interactive analysis , Improve users' pattern recognition ability of data .

 

  Design

Designing and making a visual view includes three main steps :① Identify data to graphic elements ( That is, the mark ) And visual channel mapping ② View selection and user interaction control design ③ Data filtering , That is, the results need to maintain a reasonable information density .

  Visualization should always aim at serving users . First, we need to consider the semantics of the data and the personality characteristics of the users .

Common coding methods in basic data types are as follows . When the data is not a basic data type , You can consider combining .

· Interaction ： Complex data requires more sophisticated means of presentation , In order to facilitate users' access to information , Need to provide good interaction .

· Name and classify each view .

· Animation and transition are common techniques in visualization .

  Research

· Research Based on data types ： A one-dimensional 、 A two-dimensional 、 The three dimensional 、 Time 、 Multidimensional 、 Trees and networks .

· Research Based on data state model ：（Data State Model）Chi The visualization is divided into four data conversion stages and three Chinese data conversion operations .

---

“ Accept it first , Then think about it ” 

Reference resources

https://zhuanlan.zhihu.com/p/25897580

《 Data visualization 》_ Chen weibian