I am writing an app to analyze reading levels in a K-12 environment.
My primary issue at the moment is creating a chart with a date as a dimension, and a reading level as an expression.
I can represent this data in tabular form, longitudinally for each student, with no problem:
For a specific student, the tabular data may look like:
Date Level
Spring 2011 H
Fall 2011 K
Spring 2012 N
When I try to create a chart, there is no data to display. I'm assuming this is because the letters have no context to Qlikview, and as such cannot be ordered in any meaningful way.
If I use some other value that is numeric as the expression, like Reading Accuracy (which is measured as a percentage), the chart works out fine.
Try using a dual value as expression result, with the text representation being your Level, and a meaningful numerical representation (maybe your Reading Accuracy) which can be used as numerical input e.g. for bar chart height etc.
dual( Level, [Reading Accuracy] )
edit:
Or create an inline lookup table where you link your Levels A to Z to numerials as needed:
