Control Chart from SQL query results

Hello, I ran a query to get a column of durations from a MS SQL database, and am trying to construct a control chart. What is the best way to do this? I tried to follow the example given, but there seems to be a problem because I only have one column.

Thank you

Answer 1

[Tom Lane]

If the column is a series of measurements taken over time, with no particular grouping to them, then there are charts like the "I" (individuals) chart that may be appropriate:

load spectra
controlchart(octane,'charttype','i')

Otherwise, if there are groups, you could specify a second argument that represents the grouping. For example, if each set of five consecutive measurements is taken on the same day and you want to look for day-to-day differences, then set up a vector "day" that is 1 for the first five measurements, 2 for the next five, and so on.

[Todd]

Tom,

Thank you, that was what I needed.

[Ziad Ramadan]

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