- #1
gholamghar
- 27
- 0
Hello
my question is how and with which methods Equations are derived from graphs,for example the graph below is for specific energy in open channel flows,and the equation to it is :
E=y+(q^2)/2*g*y^2
how this equation has been obtained from the graph?
if in Excel you add a trendline to this figure and then you find the equation with Excel,the best it gives you is this:y = -0.0453*E^2 + 1.6595*E - 2.3539
and this is totally different with the above equation,
so how do they obtain equations from the graphs?
thanks
my question is how and with which methods Equations are derived from graphs,for example the graph below is for specific energy in open channel flows,and the equation to it is :
E=y+(q^2)/2*g*y^2
how this equation has been obtained from the graph?
if in Excel you add a trendline to this figure and then you find the equation with Excel,the best it gives you is this:y = -0.0453*E^2 + 1.6595*E - 2.3539
and this is totally different with the above equation,
so how do they obtain equations from the graphs?
thanks
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