In our previous lesson, we focused on how to create and use Tableau's filters. In this lesson, we will discuss Tableau parameters, which are dynamic values that can replace constant values in calculations, filters, and reference lines. After this lesson, you will be able to use, explain, and create parameters. Let me show you what I mean. Parameters are dynamic values that can replace constant values in calculations, filters, and reference lines. For example, you may create a calculated field that returns true if sales is greater than 500,000, and otherwise will return false. You can replace the constant value of 500,000 in the formula with the parameter. Then using the parameter control, you can dynamically change the threshold in your calculation. Alternatively, you may have a filter to show the top 10 products by profit. You can replace the fixed value of 10 in the filter to a dynamic parameter, so you can quickly look up the top 15, 20, and 30 products. You can create a new parameter based on a selected field in the data pane, or you can create a brand new parameter. Using our superstore dataset, in the data pane, right-click on the "Profit" field, and then select "Create", and then "Parameter". In the create parameter dialog box, give the field a name. You can optionally write a comment to describe the parameter. We will call our parameter "Profit Parameter", and comment, "This is our profit parameter." We will use the float data type for the values the parameter will accept and specify how the parameter will accept values. You can select between all; the promoter control is a simple type in the field, list; the parameter control provides a list of possible values for you to select from, or range; the parameter control lets you select values within a specified range. I prefer parameter will use all values. The availability of these options is determined by the data type. For example, a string parameter can only accept all values or a list. It does not support a range. If you select list, you must specify the list of values. Click on the left column to type it value. Each value can also have a display a list. If you select range, you must specify a minimum, maximum, and step size. For example, you can define a date range between January 1, 2010 and December 31, 2010 with the step size to set to one month to create a parameter control that lets you select each month in 2010. When finished, click "Okay". The parameter is listed in the parameter section at the bottom of the data pane. Parameters are global across a workbook and can be used in any worksheet. To use the parameter, let's create a calculated field that gives us a value of high, if our profit is higher than our parameter value, or low, if our profit is lower than the parameter. Lets right-click on our data pane and select "Create calculated field". Let's call this new field profit category, and create our calculation. If sum of profit is greater than or equal to [parameters]. [profit] THEN "High" "ELSE" "Low" END, we can see that our calculation is valid. And let's click on "Okay". Now, let's put our calculated field and parameter to use. Let's drag our state category onto our worksheet, and profit onto our label. Now, we see the total profit for each state. Now, if we drag our profit category field to the colorless part, we can see that Tableau categorizes each state into high, or low profit based on color. Now, let's right-click on our parameter and choose "Show Parameter Control". The value in our parameter controls how the categories of high or low are determined. So, if we change our value to 10,000, all states with a profit less than 10,000 are low, and those with the value higher than 10,000 are high. Now, you have created a dynamic field that the user can control. So far in this course, you have learned what calculated fields are used for, and how to create new fields, how to use Tableaus quick table calculations, how to create custom table calculations, how to create and use Tableau's filters, and how to create and use Tableau's parameter functions. Now, to help refine your skills, please remember to continue practice everything you are learning. Go back through everything you have learned in this module and try to explore ways to expand on what you're learning. In the next lesson, we will focus on Tableau's maps, which are used to create charts using geographical fields. See you next time.
