Home |
Search |
Today's Posts |
#1
Posted to microsoft.public.excel.charting
|
|||
|
|||
How do I determine a y value for x ?
I create a chart from data. I now want to use that chart and data to predict
the y value for any given value of x. How do I go about doing that in Excel? Is there a way to do curve fitting to get an equation for a curve? HOw do I go about doing any and/or all of this? |
#2
Posted to microsoft.public.excel.charting
|
|||
|
|||
How do I determine a y value for x ?
You can add a trendline to a chart series. You can use the trendline formula
(be sure to use enough significant figures to get a reasonable result) or the LINEST worksheet function to get coefficients to compute Y values for known X values. - Jon ------- Jon Peltier, Microsoft Excel MVP Peltier Technical Services, Inc. http://PeltierTech.com/WordPress/ _______ "Flyrodder" wrote in message ... I create a chart from data. I now want to use that chart and data to predict the y value for any given value of x. How do I go about doing that in Excel? Is there a way to do curve fitting to get an equation for a curve? HOw do I go about doing any and/or all of this? |
#3
Posted to microsoft.public.excel.charting
|
|||
|
|||
How do I determine a y value for x ?
I will assume that the calibration curve is linear (y = mx + b)
In some cell (say D1) we can find the slope (m) with the formula =SLOPE(y-values, x-values) Something like =SLOPE(B2:B12, A2:A12) Likewise in say D2 we can find intercept (b) with =INTERCEPT(y-values, x-values) Let D3 contain the measured y-value from which you need to compute its x-value Let these values be Y and X So Y =mX + b or X = (Y-b)/m Turning this into Excel: in cell D4 enter =(D3-D2)/D1 Now having done that, you need to be able to report also your confidence intervals See http://people.stfx.ca/bliengme/Excel...onfidence3.htm -- Bernard V Liengme Microsoft Excel MVP http://people.stfx.ca/bliengme remove caps from email "Flyrodder" wrote in message ... I create a chart from data. I now want to use that chart and data to predict the y value for any given value of x. How do I go about doing that in Excel? Is there a way to do curve fitting to get an equation for a curve? HOw do I go about doing any and/or all of this? |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
How to determine the max. value? | Excel Worksheet Functions | |||
pre determine value | Excel Discussion (Misc queries) | |||
How to determine the value? | Excel Discussion (Misc queries) | |||
How to determine the value? | Excel Worksheet Functions | |||
How to determine the value? | Excel Discussion (Misc queries) |