I have a line graph that graphs test results per person (for over 30 people) after certain numbers of months since starting a program. An example of how the data is structured is below:
|Person||Months since starting||Test Score|
Months is on the x-axis (goes up to around 60), Test Score is on the y-axis, each person has their own line (for over 30 people).
Not every month will have a test score, meaning that when the x-axis does NOT have a continuous scale, the distance between Month 24 and Month 36 can look the same as the distance between Month 1 and Month 2 (which is not ideal).
But when I choose to have the scale be continuous, the data for several subjects disappears from the graph. Why does this happen?