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Choosing of X and Y axis in linearity plot
Posted: Sun Oct 07, 2007 5:29 am
by amitavaghosh
During linearity plot why we are taking concentration in Xaxis and response(area) in Yaxis. why not the opposite?
Posted: Sun Oct 07, 2007 8:51 am
by zokitano
Because x is always the independent quantity and y - the dependent quantity.
The response of the analyte (y quantity, e.g absorbance units) is always dependent on the amount (independent quantity) of the analyte (e.g its concentration).
Regards
Posted: Mon Oct 08, 2007 3:50 am
by tom jupille
For the same reason that maps are drawn with North at the top: doing it one consistent way makes things easier to interpret. In principle, the independent variable could just as well be shown on the vertical axis, but that would confuse people.
Posted: Mon Oct 08, 2007 10:07 am
by AdrianF
It is a convention but it is important to stick to it if you are calculating the regression mathematically.
The calculation of the line of regression assumes that the x values are known precisely and all the variation is in the y values. (eg peak area or height in HPLC)
Posted: Tue Oct 09, 2007 5:20 pm
by amitavaghosh
thanks dear all