The recursive call was a typo. Things continue to evolve. If you have time, take a look. I may have hit a limitation on what some of the Solve functions can do. This NSolve works fine without units.

Attachments:

Unit Plot.nb

Here we go again! For some reason in the definition of velocity time is getting the units of s^2.

I figured it out.

Attachments:

Unit Plot.nb

Not sure. Try reading through the help pages for Plot and Quantity. The reason your code didn’t produce the desired outcome was that you omitted the Quantity function. Hence, the argument passed your user defined function z[] was treated as an expression corresponding to t*”Seconds”. As this expression evaluates to a non-numeric value, it couldn’t be plotted.

All he best,

Ian

Try adjusting the arguments passed to your Plot function to this...

Plot[z[Quantity[t,”Seconds”]],{t,0,10}]

All the best,

Ian

Try this...

A notebook is also attached.

Here I've evaluated the Quantity[...] functions in place as I think it makes documents more readable. On a Mac, this is done by selecting the part of the expression you want to evaluate in place and pressing CMD-SHIFT-ENTER. Once evaluated, you can click into the Quantity panel and edit the numeric value. Alternatively, you can get a plain unit (without a value) by using the expression Quantity[None,"Unitname"]. Using this approach you can keep the quantity value outside the quantity panel. An example is given at the end of the attached notebook.

Hope this helps,

Ian

Attachments:

PlotWithUnits.nb

Belated "Thank You." This has been very useful in evaluating functions but I don't have enough knowledge of Mathematica to extend it to other uses. For example when I try:

Plot[d[t], {t, Quantity[0, "Seconds"], Quantity[10, "Seconds"]}]

I get axes but no plot. Is there a part of the documentation I should read?

GOGO

You could limit your function to only accept units of time:

ClearAll[d]
d[t : Quantity[_, unit_]?(CompatibleUnitQ[#, "Seconds"] &)] := 10*t^2
d[Quantity[5, "Seconds"]]

or, similarly, one could use UnitDimensions to check if the input has time-dimensions... Of course the 'variables' 10, 5, and 25 in your equation should have commensurate dimensions...