Pspline or Cspline slope control

[ptc-3242727]

Hello,

Does anyone know how to control the slope (or end tangency) of a pspline or cspline curve? I'm using MathCad 15.

I want to input definition points (using x and z vectors) to create a spline equation z(x). The part I'm having problems with is trying to force the spline to have zero slope at the definition points. I've attached a sheet to help with the explanation. Any ideas?

In case this might help, I'm writing the sheet to evaluate a post-tensioned concrete beam with multiple spans. The function will be used throughout the sheet to define the tendons.

[AlanStevens · Accepted solution]

Attached shows a (slightly cheating!) way to do it.

Alan

[ptc-3242727]

Yeah, I think that does what I want! It is a bit of a cheat, but it seems as if MathCad doesn't have any built in functionality with the spline functions.

I noticed that lspline (linear end points) pushes the curve closer to 0 slope at the definition points.

Thanks for the help.

Sean

[AndyWesterman]

Alternate method using 'Find' - a little easier to modify inputs

Regards

Andy

[ptc-3242727]

Thanks!

It definitely doesn't hurt to have multiple solutions.