bbqsrc/dvchart — Issue #1: Blank areas in percentage graphs
Author: snomos
Created: 2011-12-11 10:40:03+00:00
State: open

I was looking at the percentage graphs, and the blank areas. I don't know the exact cause, but I will go through one example to try to identify some clues. The example is the NOB goldstandard test, the suggestion percentage graph.

The graph looks fine, except that the first two datapoints (ie test results) are empty for these categories:

- only wrong suggestions
- no suggestions below third positions

that is, those areas are white in the graph until we reach the third datapoint/test result date.

Now, if I look at the actual test data for the first test results (the source xml), it seems that the test data set has been very small. Here are the raw figures:

* # of words: 480
* # of spelling errors: 28
* # of correctly detected selling errors: 18

Of these 18 correctly detected spelling errors, they distribute like this:

* # in 1. position: 14
* # in 2. position: 1
* # in 3. position: 1
* # below 3. position: 0
* # only wrong suggestions: 1

That is, there is no available data for most of the categories that are white in the graph - suggestions with position 4, 5, and below 5. There is one case of only wrong suggestions, but the display of that info is probably destroyed because of the non-display of the other categories.

What I suspect is that missing data (as opposed to existing data with value zero) is not accounted for somewhere, and this causes the whiteouts in the graphs. At least that seems to be the case in this example.