Problems with interpolating data in Mathcad

[AK_10948685]

Hi everyone,

I have a problem with interpolating data in Mathcad. Please see the attached file. In Excel, I have defined materials and temperatures. I want to replicate this in Mathcad so that when I select the material and temperature, the corresponding stress value is automatically displayed. Additionally, for temperatures ranging from 100 to 250, if I select a temperature like 120, the stress value should be determined through interpolation based on the material and temperature.

I have also attached my Mathcad file. I approached this in two ways: The first method works for standard temperatures like 100 and 150 but shows an error if I select a temperature like 120 that is not explicitly defined. The second method involves interpolation but only for one material. If I have multiple materials, I have to repeat the process for each one.

If anyone has encountered and solved this issue before, please let me know.

note - these materials and temperatures are not standard and are used only for demonstration purposes.

[Werner_E · Accepted solution]

Simply use

in your second method!

The row selector choses row #a in the data matrix corresponding to the material selected via the drop down and the transpose operator turns the row vector into a column vector which is needed for "linterp" to work.

You may also bypass the definition of the variable "m" and use that expression directly in the "linterp" function:

[AK_10948685]

Hi Werner,

Thanks for this solution. I made some changes, according to me. Please see the attached Mathcad file.

[ttokoro]

[AK_10948685]

Hi ttokoro,

This is a good idea. We can plot a graph. I will use this.

[ttokoro]

 f/ MPa for 2220 MPa line.