Automated Interpolation Using  

Thank you very much for this clear, methodical, and thorough presentation of the topic. I inherited a spreadsheet to use as a reference for a hydrologic model and was stumped at the use of Forecast, Index, and Match without your helpful guide! Thank you again!!

Thank you. Very useful interpolation method. To facilitate, I copied the final formula here: FORECAST(A3,INDEX($H$3:$H$9,MATCH(A3,$G$3:$G$9,1)):INDEX($H$3:$H$9,MATCH(A3,$G$3:$G$9,1)+1),INDEX($G$3:$G$9,MATCH(A3,$G$3:$G$9,1)):INDEX($G$3:$G$9,MATCH(A3,$G$3:$G$9,1)+1))

Very nice, clearly explained a complex functionality. Thanks

Thank you Very nice, clearly explained

Thank you sir, this is extremely valuable. I can now create my own civil engineering excel sheets....without having to buy extra software.......🙂

Works perfectly! Thanks.

Very helpful. Appreciate that.

Hello and thank you much for this. i used it at it worked 🙂. However I have several sets of data to interpolate for. That is several sets of data for known a, which will give a different output for the interpolation of a (unknown a's). How do I do this with at once for say 100 columns of known a's?

Hey what if the know values are integrrs ..i have some postive values and some negative values