topic Re: Plot line has missing segments in Mathcad

Plot line has missing segments

LH_13783026 — Thu, 10 Jul 2025 12:13:08 GMT

Hi all,

I have an issue with plotting a function on Mathcad Prime 11. For some reason there are missing segments in the plots of my shear-force diagrams. I'm not sure why this is happening, other plots I have made seem to work fine - any guidance would be much appreciated.

The plots and respective functions are on pages 9 and 17 of the attached document. Thanks in advance

Re: Plot line has missing segments

terryhendicott — Thu, 10 Jul 2025 12:31:50 GMT

Hi,

Include the two points of legs in the vector of x2. In the following worksheet have done this.

Cheers

Terry

Re: Plot line has missing segments

Werner_E — Thu, 10 Jul 2025 15:13:34 GMT

What Prime is doing is mathematically correct - a vertical line can never be the graph of a function. A step means that there is nothing inbetween.

But I understand that you are used to see that vertical line segment.

Solution is to use a vector for the abscissa values instead of a range. In Prime 11 you can use the convenient "vec" function to convert a range into a vector.

Using the vectors solves your problem.

It depends on the way the functions V and V2 are defined if vectorization when calling them with a vector argument is mandatory. In your case it would not be necessary as Prime would apply automatic implicit vectorization, but I consider it good style to explicitly apply vectorization.

Re: Plot line has missing segments

LH_13783026 — Thu, 17 Jul 2025 09:26:37 GMT

Hi Terry,

Thanks for your response, I now realise that the increments I had used for x and x2 were too large, effectively skipping the points where those loads were applied.

Many thanks

Re: Plot line has missing segments

LH_13783026 — Thu, 17 Jul 2025 09:27:44 GMT

An interesting solution. I'll have to give this a try, seems like a nice clean way of handling this issue.

Many thanks

Re: Plot line has missing segments

Werner_E — Thu, 17 Jul 2025 14:55:48 GMT

@LH_13783026 wrote:

An interesting solution. I'll have to give this a try, seems like a nice clean way of handling this issue.

Many thanks

LH

Yes.

Actually Terry also used vectors instead of ranges in his solution. I just wanted to show that its not necessary at all to add the two special values.