From the course: Machine Learning with Data Reduction in Excel, R, and Power BI
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Removing or replacing null values
From the course: Machine Learning with Data Reduction in Excel, R, and Power BI
Removing or replacing null values
- [Instructor] In data sets and especially large ones, we'll often see blank values that occur within a column or columns. They occur for many reasons, for example, the field might be an optional input, it might not have been collected at the time or the measurements are inaccurate. Mitigation strategies for missing data values, include the entire row, replacing the missing value with an actual value, or making the missing value a zero. If we look at this sample of the New York City (indistinct) data from the year 1900, we can see that the PRCP field, has multiple blank values. It also has many values that are populated. To account for these empty temperatures, let's calculate the average PRCP for the entire column and we'll put it at the top. If we calculate the averages by just hovering over the columns, we can see that including the null values, these empty cells doesn't impact the average calculation. Now let's…
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