topic Re: Return only the KP value when F is greater than 0 in Mathcad

Return only the KP value when F is greater than 0

davidlimtw — Mon, 19 Jun 2023 11:05:31 GMT

Dear All,

I am trying to write a program to return the only KP values when F is greater than 0.

Re: Return only the KP value when F is greater than 0

davidlimtw — Mon, 19 Jun 2023 12:25:19 GMT

I would like to add also a function to filter to return only the KP where F > 0 and another matrix showing the only F > 0 values.

Re: Return only the KP value when F is greater than 0

Werner_E — Mon, 19 Jun 2023 12:40:50 GMT

Again its not really clear what exactly you expect as result and giving one or two examples would have helped.

In the following approach I assumed that you want a vector with the values of KP but replace the original value if the value in F at the corresponding position is negative.

Here is a short approach using vectorization

We can use a table built with augment to check the results

And here is a more "natural" approach with a function using a for loop

You can replace the 0m by NaN or whatever may be appropriate.

We can check if both ways return the same result

Using the if-function we can write it less space consuming

One may think that we could simply vectorize that if-function

but this does not work

because Prime does not allow to vectorize comparison operators like the < directly, but we are allowed to vectorize a function which uses the comparison:

Prime 9 worksheet attached

Re: Return only the KP value when F is greater than 0

Werner_E — Mon, 19 Jun 2023 13:07:06 GMT

@davidlimtw wrote:

I would like to add also a function to filter to return only the KP where F > 0 and another matrix showing the only F > 0 values.

Examples always would be welcome to clarify what exactly is needed.

A I understood it now you want the values in both vectors removed when F is zero or negative so only the positive values in F remain and also the corresponding values in KP?

Could be done in many ways, one is shown here