Forum Discussion
column data linear fit the linear formula Vs = A +B*Vp -C*NPHI - D*RHOB
A little Help please, I have column data of the inputs Vp, NPHI and RHOB vs depth and wish to find best fit to Vs also on same depth index? The starting point of the formula would be Vs = 1.234 ...
Tom_SIIImaybe I'm too simplistic here but I assume you have 3 columns of data that correspond to Vp, NPHI, and RHOB, so I would add 4 rows to the top of the data for parameters A,B,C,D and then make the formula in column 4 (starting in row 5) =d$1+$a5*d$2-$b5*d$3-$c5*d$4
the strategic use of $ to fix either the row or column makes so you can fill down to make the calculation for every row. Then you can go to the next column and adjust A,B,C,D (manually or using a formula) and fill right to calculate the values with the new A,B,C,D.
hope that helps