I am trying to do a chart over time and expect there to be a really simple solution to this but I think it is a case of "easy when you know how".
I want to do a chart of distance (y axis) and time (x axis).

I am taking the data from journeys made on my bike, where my GPS gives me a list of points that compare distance travelled over time along the journey.

I want a chart where I can compare the progress of trips as a series of journeys (in the form of lines) against each other.

I believe it is an x/y scatter graph I need but the issue arises that the data for my journeys has no pattern. So the readings are not regular eg time is not at regular intervals or distance not at regular intervals. The number of points in each data series varies as well.

I need to create a graph that has a set x (time) and y (distance) axis and then I can plot the points of each data series (journey) to give me a line for each journey.

Please someone tell me this is easy..