using vlookup to find a value that is equal to or greater than a value
I need to find a way to use a vlookup function to find a value that is equal to, or greater than, a value. I have a value that dictates the use of a certain size of a device. The device size can be oversized but not undersized. So if I have a determined value of say 5.5, device A is good for 5 and device B is good for 6, then I need to return data for device B from the evaluation.
You forgot to state which version of Mathcad/Prime you are using.
In Mathcad 15 you can use a function from the (unsually included) Data Analysis Extension Pack), "Lookup" (note the capital "L"). In Prime you may use "lookup" (captial "L" or not does not matter here) the same way.
You may also use Vlookup or Match in a similar way. Replace the "0" by the value of ORIGIN or by the system variable ORIGIN.
Those function use a fix precision based on the value of the system variable TOL to decide if something is equal or not.
So sometimes (when you don't want to mess around with TOL) its better to rely on a small self written function like the one Luc has shown.