Checking if point is above or under the function

[iwearplimsolls]

Hi all,
I have several functions which are similar but separated from each other on Y axis. I must check between which functions the point is located to determine how many hinges I must use for a door. Can you tell me how to do it?
Thanks

[etaf]

not sure what you mean
Have a read of the yellow banner and post a sample spreadsheet - with some expected results and why

[iwearplimsolls]

In the attachment you can find graph where these functions are. The Y axis is weight and X axis is width of the sash. Based on this two values I want excel to determine between which of the functions on graph is the point located and by that how many hinges I need.

[Richard Buttrey]

Which 'point' are you talking about?

A worked example would help considerably. Tell us what you want to see reported and how you arrive at that answer.

[iwearplimsolls]

I'm talking about point with coordinates (X,Y) (I've explained what X and Y axis are eariler).

So I have specific weight and width of the sash. Given this figures you get coordinates of point A for example. This point should be located somewhere on the graph. Each area between two functions represent specific number of required hinges. I want excel to calculate number of needed hinges. In the attachment you can find spreadsheet where I tried to explain this as specific as I can - I am really green in excel, sorry.

[MrShorty]

If I understand what you are trying to do, here's how I would do it:

1) Chart trendlines are nice for quick visualizations, but they are not referenceable in spreadsheet formulas, so they are not very useful when you want to actually use them. All of the chart's trendlines are linear functions, so I prefer to use the LINEST() function to perform the regression directly in the spreadsheet. For example, a power trendline is ln(y)=ln(b)+x*ln(m) which is a simple linear function, so I would perform these regressions in the spreadsheet as =LINEST(LN(B3:B12),LN(A3:A12)) in Arkusz1. Quadratics are similar -- see the LINEST() help file: https://support.microsoft.com/en-us/...rs=en-us&ad=us If you are content to hand enter the coefficients from the chart to the spreadsheet, this step is not necessary.
2) In Arkusz2, I can now build a lookup table that will relate mass/weight (Assume this is E16) to number of hinges based on width (assume this is B3).
2a) In J5:J9, enter the number of hinges: 5,4,3,2,1
2b) In I5:I9, enter the appropriate formula for mass/weight for the corresponding number of hinges. I9, for example, would be =36759*$B$3^-0.98868 (or references to the cells containing the parameters). Repeat for I5:I8.
3) At this point, a simple lookup function will give the number of hinges INDEX($J$5:$J$9,MATCH(E16,$I$5:$I$9,-1)). Note the approximate match descending order option for the 3rd argument of the MATCH() function.

If I understand what you are trying to do, that's how I'd do it.

[Richard Buttrey]

I think this can be done with some simple MATCH() INDEX() functions and some helper Rows which reference the XY values in the main table.

See attached

[iwearplimsolls]

Thank you very much guys, I didn't think this is so simple