Graph works in Mathcad15 but not Prime 3.1?

I can only look at your version 15 file (I don't have 3.1.)

One possible problem  is units:  in version 15 you need to divide your plot by the units you want; you have put in commas, making your units a second plot (note the dashed blue line under kips.)  Since Mathcad recognizes both kips and in as values it will plot your function (and not plot the blue line,)  but I'm not sure what that does to Prime after translation.

Daniel Sochor wrote: Attached is a short worksheet created in both Mathcad 15 and Prime 3.1. The graph at the end of the worksheet works in 15 but not Prime 3.1. I've attempted to make them the same but there is an error in the 3.1 program. Might folks know what is the error in the Prime 3.1 program?

Looks as if there may be a bug in Prime 3.1, or perhaps a misinterpretation on my part of how the summation operator works in Prime.  The problem arises in this expression (copied from the M15 version as I can just select, copy and paste ... just as I want):

Earlier in your worksheet, you've got i defined as a range variable (i=[1 2]).  It appears as if F_s is passing the range variable to F_si rather than the value that the summation iterator value.   Changing i in the summation to k makes a graph appear.

Stuart