Data understanding described (Part 2): Introduction to visual variables

Article in my data viewing series. See the past article: “Data eye is defined: What is and why is it important.”

Therefore, you have now learned the basic view of what is referring to Data Visuact and why is it an integral part of the data science ecosystem. (If you are not familiar with this, make sure you check the article linked above.)

As we discussed in the previous article, the basic idea of ​​seeing data find a successful method of representing the various types of species in a visible way.

The main focus of the key significance of the representation of the representation is known as a visualized channel. A A cheating cheat station The effectiveness of the methods in which numbers, documents, or other data method is being modified to a symbolic sign. The best way to think about as a visual feature corresponds to all or part of your data. The active data recognition usually applies many channels to view the books of different data features.

In this second article, we will enter details of visual viewing stations and find practical practice to destroy the complex image in parts of its elements. This will prepare you for designing yours in the near future.

The final introduction is a variable

In his 1967 work, Semiciology of graphicsFrench Cart Tarcos Jacques Bacques Bacques Bactin describes seven “Retinal” variable, named because the human eye retina is sensitive [1]:

1. Position (such as linking to graph)
2. Quantity
3. Kind
4. Color Hue
5. The number of colors (light in the dark)
6. Insight
7. Texture

Although Bertin publishes his work decades ago, his visual variables remain a very good guide for modern formation. In the first phase of eye contact, it is a good practice for visual variables available and determines which ones use them to change to data.

This can be a confusing idea and easily understood by example. The illustration below, is often viewed as a good use of the eye, designed and dragged by Charles. Shows Napoleon's failure attack in Russia.

This is a simplified and translated the reading map; Real, look here [2].

Which visual variable is used in the above graphic? (Suggestion: There are a few.) As a job, get out of pen and paper and try to determine this personally. We will go in detail in detail.

To increase the effectiveness of material material

The best variables you can use to get something based on data. Here, we will look at three types of data:

1. Stubborn: Number data that has the correct environmental order of mathematical activities (ie, it is reasonable to add / discharge / repetition / dividing individual data). For example, income and age is different.
2. Bite: Category Data (ie, non-number data that can take a fixed number of prices) that still is an environmental order. If you have ever taken the survey about responding decisions such as “firmly agree,” Be a close, “” and “disagree,” then you have seen active data in action. While mathematical performance in this data does not make sense, different values ​​are still able to order from the “best” to “worst,” to talk.
   • This includes the differences that may have a command unless “calculated,” as traffic patterns.
3. Observers: Data with categories without a natural order. A great example of this color. While it is possible to distinguish between different colors, they do not have the evolution. (This also explains why color is the best information of the standard variations, as we will see below!)

Important: Just because the variable is a number does not automatically do. For example, zip codes have numbers, but they do not have the order of nature, and one can perform mathematical activities. Therefore, zip code a observers Variable.

The following table, diversity designed by the Jock D. Mackinlay and the Stuart Card, emphasizing effective performance of visual variables relating to data type [2]:

The main points are important for these areas:

• Position is the best way. For example, the name of the words in X-axis and blood pressure in Y-axis uses the position of different variations and fluctuations of measure, respectively.
• After a position, a desire for the desire for each variable type. This is important to know because if you put a number of variables, you will eventually use anything other than position because we are already used (usually in a 2-D graph with two axes).
  • Height is the extension of the position, but it is especially useful in limited comparisons.
  • The plural and the saturation is good for the variety of appointment, as your viewers do not need to find specific amounts – they just need to see levels.
  • Hue and situation functional on words variations, making it easier to see the difference differences.
• Some options are completely from because they are simply unreasonable. For example, the make-up is not a billing decision for variations of rate or planning, because there will be no way to compare prices or understand orders.

Now, let's go by the example of how to distinguish visual channels in detail.

Map of Minard: Variable demolition

Let's see MINARD's map of Napoleon's attack together. Here it is easier. This example is taken from Edward Tufte's famous bookings to view photos, visible display of measurement data [3].

Careful study of this map indicates that Charles's Mastery of visual channels as a sake of his visual displays different different:

1. Area of ​​area (plural): Stop It is used to show Napoleon's army area in more than 2-D (DO, therefore this is two variables. The attack began on the left of the map, on the Polish-Russian border. And we can see that occasionally, parts of the soldier branch to various locations as part of Napoleon's plan.
2. Area of ​​area (plural): Look above.
3. Time (Size): When we look at it, we see that different points during the X-axis list in the chart below viewing the eyes. Again, the stop used to indicate this variable.
4. Temperature (size): The temperature is organized in connection with time in a chart under the map. Stop used again, this in Y-axis.
5. The number of forces left in army (size): Wide of the situation that travels across the map represent the number of soldiers in Napoleon's army. Clearly, as the attack moves forward, Napoleon's troops are small and thin. They finally returned to Poland with 10,000 living soldiers only for 422,000.
6. The direction of the army (your): Color is used to show how the army goes to different positions. Beige / TIGE color

In his book [3]Tufte refers to the MIBAR map as possible “the best image of the statistics you have been drawn.” Studying can encourage us to light wise ways to put our details on viewing.

Final thoughts and looking forward

With this second article, you have learned the basic idea behind the mind creation: visible material channels. As you think about what you have learned, keep the following important points in mind:

• The selection of a visual channel can usually do or break the eye. You may have a well-designed picture, but if it is difficult to describe the visual channan translation, your viewers will know what you are trying to do.
• The position is higher than all forms variable, but there is a limited space in 2-D area. Thus, think carefully what variables showing positions; They are used to being very important.
• Try different shape! No complete “single” solution. Instead, you have to review and again and again come to the complementary point.

In the following article, we will talk about important nominations and how strategies appear and extend over the past decades. Until then.

Progress

[1] Semiology of graphicsJacques Bertin (J. Ronald Eastman)
[2] https://ApeofRevolution.org/200-bject/flow-map-abap-nap-abaloons-invases/
[2] Reading in the identity of information: Using the thought of thinking (Card, Macklay, Nashneiderman)
[3] A visual display of the details of the abundanceEdward Tufte