Skip to main content
S
SFares14-Alexandrite
14-Alexandrite
June 8, 2025
Solved

Constant multiplied with the curvature y"

  • June 8, 2025
  • 2 replies
  • 1199 views

Hello,

Please see attached file. How can i get a constant value for (EI) to be multiplied by the results of the curvature y"(x)?

 

Thanks,

Sam

Best answer by Werner_E
 But then your range variable "x" must consist of integers only.

Which makes your approach VERY limited, especially given that an additional constraint is that the range variable must start with ORIGIN as the first value!

Also it seems that @SFares  wanted to define a function, not just a vector of values.

 

For more flexibility you could use something like

Werner_E_0-1749415315666.png

but again M is not a function but just a vector of values.

You may also note that it was necessary to use the (IMHO silly and wrong) alternate way of accessing vector elements by using the vector as if it would be a function, x(i) instead of x[i.

If we use the correct vector index here, Prime throws an error which seems to be related to the bug I mentioned in my previous reply.

Werner_E_1-1749415481123.png

Or compare this

Werner_E_2-1749415549983.png

Sure a bug.

 

 

 

2 replies

W
Werner_E25-Diamond I
25-Diamond I
June 8, 2025

Ranges should only be used in three cases:

1) To index the elements of a matrix or vector

2) To define the abscissa values for a plot

3) To create a for-loop in a program

 

You defined x as being a range but used it for other purposes.

You should define x as being a vector rather than a range!

 

While playing with your sheet I found what i consider to be a bug in Prime. A derivative using the prime operator throws an error when used vectorized -> Bug in Prime with vectorization and prime operator..

 

See attached P11 file for further informations

 

 

    S
    Sergey15-Moonstone
    15-Moonstone
    June 8, 2025

    Hello.

     

    My best guess is to try and use subscript "x" in the definition of "M". But then your range variable "x" must consist of integers only.

    See attached mathcad.

     

    Best regards,

    Sergey

    W
    Werner_E25-Diamond IAnswer
    25-Diamond I
    June 8, 2025
     But then your range variable "x" must consist of integers only.

    Which makes your approach VERY limited, especially given that an additional constraint is that the range variable must start with ORIGIN as the first value!

    Also it seems that @SFares  wanted to define a function, not just a vector of values.

     

    For more flexibility you could use something like

    Werner_E_0-1749415315666.png

    but again M is not a function but just a vector of values.

    You may also note that it was necessary to use the (IMHO silly and wrong) alternate way of accessing vector elements by using the vector as if it would be a function, x(i) instead of x[i.

    If we use the correct vector index here, Prime throws an error which seems to be related to the bug I mentioned in my previous reply.

    Werner_E_1-1749415481123.png

    Or compare this

    Werner_E_2-1749415549983.png

    Sure a bug.

     

     

     

      S
      SFares14-AlexandriteAuthor
      14-Alexandrite
      June 9, 2025

      Thank you, Werner!

       So what made you use x(i) knowing x[i does not work, as if x(i) is a function? As you said, It is strange that mathcad accepts x(i) and not x[i

       

      Regards,

      Sam

      Terms & ConditionsCookie settingsAccessibility statement