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Tableau is a Data Visualisation tool that is widely used for Business Intelligence but is not limited to it. It helps create interactive graphs and charts in the form of dashboards and worksheets to gain business insights.
Types of Visualisation discussed in this blog
Line chart
Pie chart
Donut chart
Sunburst chart
Scatter plot
Line chart
Line charts, especially useful in the fields of statistics and science, are more popular than all other graphs combined because their visual characteristics reveal data trends clearly and these charts are easy to create. A line chart is a visual comparison of how two variables—shown on the x- and y-axes—are related or vary with each other. It shows related information by drawing a continuous line between all the points on a grid. Line charts compare two variables: one is plotted along the x-axis (horizontal) and the other along the y-axis (vertical). The y-axis in a line chart usually indicates quantity (e.g. dollars, litres) or percentage, while the horizontal x-axis often measures units of time. As a result, the line chart is often viewed as a time series graph. For example, if you wanted to graph the height of a baseball pitch over time, you could measure the time variable along the x-axis, and the height along the y-axis. Although they do not present specific data as well as tables do, line charts are able to show relationships more clearly than tables do. Line charts can also depict multiple series and hence are usually the best candidate for time series data and frequency distribution. Vertical bar charts and line charts share a similar purpose. The vertical bar chart, however, reveals a change in magnitude, whereas the line chart is used to show a change in direction.
Here in Columns it is Month(OrderDate) and in Rows it is Sum(Sales). For every month we get the sum of sales and we can add trend line to see the trend of sales ,for this line chart.Click on Analysis on the top select dropdown, take the Trend lines-select show trend line.
A line rising in height as it moves from the left to the right side of the chart indicates an increasing trend. The opposite, a line decreasing in height, indicates that the line has a downward trend.
Pie chart
Pie chart is circle divided to slices. Each slice represents a numerical value and has slice size proportional to the value. Pie chart usually shows the component parts of a whole. Sometimes you will see a segment of the drawing separated from the rest of the pie in order to emphasize an important piece of information. This is called an exploded pie chart.
Pie Vs Bar chart
When displaying statistical information, refrain from using more than one pie chart for each figure.Two pie charts side-by-side, where a grouped bar chart would have shown the information more clearly. A user might find it difficult to compare a segment from one pie chart to the corresponding segment of the other pie chart. However, in a grouped bar chart, these segments become bars which are lined up side by side, making it much easier to make comparisons.
Inorder to get a pie chart,Use Marks card- Drag Segment to color, SUM(Sales) to Angle,SUM(Sales) to size .Select Pie from the Dropdown below Marks
Here ,by default it is taking colors,you can change the color by selecting color clicking color option in Marks.
Inorder to get the text in the chart -Drag Segment and SUM(Sales) to Label.
For Pie chart Dimension dragged to color and measure dragged to angle and size of Marks.
Donut chart
A donut chart, in its simplest form, is a pie chart with its center cut out to look like a donut. At first glance, this may not seem to serve a much greater purpose than to create aesthetic variety. However, a donut chart helps avoid confusion around the area parameter that often trips people up in a pie chart.
We have seen Dual Axis in the previous blog (named-"All you want to know about Bar charts").Here we have to make Dual Axis with AGG(SUM(0)) or AGG(AVG(0)) to duplicate the pie chart into two
Remove all the dimension and measures from one pie chart,this is just to display the total sum of sales.In a Donut chart always we have to show total no in the middle circle and the data you want to represent in the outer ring.
For Donut chart, you have to make Dual axis adding AGG(SUM(0)) or AGG(AVG(0)) two times to the rows.One Axis we use the above pie chart's same parameters to marks card, as shown in the picture above.Another axis is for getting total no of Sales we need a circle with SUM(Sales) in it,which gives sum of all segment's sale.To make it dual axis click second AGG(SUM(0)) ,you get dropdown, select Dual axis from the dropdown.
Here we can see a chart which shows different Segments and their SUM(Sales).Total sales we get in the inner circle.
We can remove the unwanted lines to make it look better.For formatting we can select format option on the top and remove all the Lines, you can give option None for each line.
For removing Dual Axis lines just right click on the axis and deselect show header option.
Formatting chart,deleting unwanted lines
After formatting Donut chart looks like this.You can view it in presentation mode.Here inner circle i have given black color,as the background color is black ,so that it looks like a Donut.You can select background color of your choice using Shading option for worksheet.
Sunburst chart
Sunburst chart, known by multiple names such as ring chart and radial treemap, is used to visualize a hierarchical dataset. It shows hierarchy through a series of concentric rings, where each ring corresponds to a level in the hierarchy. Each ring is segmented proportionally to represent its constituent details.
In this chart outer ring is showing Category and inner ring shows SubCategory for each Category.Innermost ring shows sum of sales.
You can see for each category like Technology corresponding subcategory like Machines,Paper,Phones etc..
Here we have used calculated field Position used MAKEPOINT(0,0) to get center position
Click on position calculated field or Drag the above calculation (which is a geographic field) to the detail shelf to create a single point on a map.
Add another layer by simply dragging ‘Position’ to the Marks Layer as shown above.Make a hierarchy for Category.
Drag it to outer ring.Give color to category and subcategory.
Innermost ring Middle Ring Outermost Ring
You can see three charts in the Marks layer.Outermost layer represents the category ,middle layer represents sub-category and inner circle represents the total sales.
Sort color according to sum of sales in descending order.Here you have to select Field ,give sales as field name.
A donut chart is effectively a pie chart but with a hole or empty space at the center, while a sunburst chart displays relationships across multiple tiers of categorical dimensions.
Scatterplot
In science, the scatterplot is widely used to present measurements of two or more related variables. It is particularly useful when the values of the variables of the y-axis are thought to be dependent upon the values of the variable of the x-axis.
In a scatterplot, the data points are plotted but not joined. The resulting pattern indicates the type and strength of the relationship between two or more variables.
For getting a scattered plot you need two measures, one in rows and one in columns, which might be related to each other.To find if they are dependent on each other in any way, we can add a trend line to see if both are directly proportional or inversely proportional to each other.
For a scatter plot we have to deselect the aggregate measures,which you get as a dropdown from Analysis which you can find on the top of worksheet.
Trend lines reveal the overall direction of the data in a chart. Trend lines can help you see patterns and make predictions from otherwise random-appearing data.Uptrends are marked by rising data points, such as higher swing highs and higher swing lows. Downtrends are marked by falling data points, such as lower swing lows and lower swing highs. Many traders opt to trade in the same direction as the trend, attempting to profit from a continuation of that trend.
This blog we have seen commonly used visualizations in Tableau.Let us explore more visualizations in the coming Blog.Thanks for reading my Blog.
Happy Learning!!!