# Plotting points generated in the Spreadsheet from a Slider for Time

Simon Dakeyne shared this question 2 years ago

I have had an Excel spreadsheet for Simply Ages that plots the trajectory of an object peforming (or not!) complete loops as often attempted by stunt riders on a motorbike... with incomplete loops ending in parabolic falls off the loop etc etc.

I thought I would prefer a 'real-time' version in GGB, with the Time generated by a Slider, so one could see the object slowing as it got higher up the Loop etc (rather than a simple all-in-one complete path).

The sticking point is that all of these positions can only genuinely be plotted using step-by-step (line by line in the spreadsheet) increments in the instantaneous speed (dependent on the previous value of theta on the loop). So I have the algorithm:

Slider defines Time incrementing in say 0.01 steps.

This is 'recorded' in the spreadsheet (irritatingly in the first free column AFTER the columns calculating values for angular acceleration, velocity, angle itself, and thence X and Y coordinates).

I now want to plot these coordinates as Time increases due to the Slider. ie Time goes by steadily, and the points are plotted in 'real time'...

Whenever I try to 'Record' the Slider values, and then use this column of spreadsheet entries to calculate the rest of the spreadsheet, the whole thing crashes - either returning rows of ? signs, or indeed blank cells where there had previously been formulas entered.

Am I going about this the wrong way, and it's the order of entries I need to be careful with, or is this (as I think) a bug in the Record function that needs looking at?

Even if all I can end up with is a plotting of the coordinate columns as I manually drag the Slider for Time at a regular pace, I would be happy. It's the not being able to plot an array of data that hasn't yet been defined that irritates me!

Anyone else tried to plot data one by one, rather than all in one go?

Help!