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oyais
India
7 Posts |
 Posted - 08/05/2013 : 03:35:18 AM
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PLease let me know how to calculate overlap or common area under two curves using origin 8.5
oyais |
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Shirley_GZ
China
Posts |
Posted - 08/05/2013 : 05:48:38 AM
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Hi Oyais,
The Integrate gadget can be used here.
First, use this gadget to calculate the area under each curve, area1 and area2(without baseline by default, integrate from the straight line y=0). Then go to the Preferences dialog, set the baseline as one of the curves to calculate the absolute area between these two curves, area3.
overlapping area = (area1 + area2- area3)/2
Area1:
Area2:
Area3:
Shirley
Originlab Technical Service Team |
Edited by - Shirley_GZ on 08/05/2013 05:53:13 AM |
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oyais
India
7 Posts |
Posted - 08/06/2013 : 03:01:12 AM
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Sir i need to calculate the common area or overlap area(highlighted area as in fig.) under two curves as shown in the fig attached . I also have similar graphs but i have unable to calculate common area please guide.
oyais |
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rlewis
Canada
253 Posts |
Posted - 08/06/2013 : 6:29:19 PM
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If you are willing to do a little OriginC progamming the following OC function should do ...
double GetCommonArea(Curve CurveA, Curve CurveB)
{
Dataset dsX, dsY;
vector<double> xCurveA, yCurveA, xCurveB, yCurveB;
if(CurveA.CopyData(xCurveA, yCurveA) == true && CurveB.CopyData(xCurveB, yCurveB)==true)
{
if(dsX.Create(xCurveA.GetSize()) == true && dsY.Create(xCurveA.GetSize())==true)
{
for(int i=0; i<xCurveA.GetSize(); i++)
{
dsX[i]=xCurveA[i];
double yVal=(Curve_yfromX(&CurveB,xCurveA[i]));
dsY[i]=min(yCurveA[i],yVal);
}
Curve CommonArea(dsX,dsY);
if(CommonArea.IsValid()==true)
{
return (area(CommonArea));
}
}
}
return NANUM;
}
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oyais
India
7 Posts |
Posted - 08/08/2013 : 12:51:13 AM
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is it necessary to do programming if yes pls lemme know how to use origin c programming to input this function
oyais |
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greg
USA
1378 Posts |
Posted - 08/08/2013 : 12:05:10 PM
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If your data shares the same X column, then the solution is simple:
Add a column to your worksheet.
Select the column and press Ctrl+Q (opens Set Values dialog).
Enter this expression, using your two Y column numbers or names:
min(col(B),col(C))
Click OK, then integrate that column to get the area.
If your data does not share the same X column, then you first need to create a common X column then use Analysis : Mathematics : Interpolate/Extrapolate Y form X to create new Ys and do the above with this data. |
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oyais
India
7 Posts |
Posted - 08/08/2013 : 10:41:44 PM
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@rlewis, programme showed errors.. i couldnt do it
@ Greg. I am sorry Greg could get u..
Kindly explain your procedure with an example and yes my dta doesnot have common x.If you wish i can forward the origin file to u via email.
Thanks!!
oyais |
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rlewis
Canada
253 Posts |
Posted - 08/09/2013 : 01:13:07 AM
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I've tested the function and could find no error ...
What is/are the nature of the error/errors that you found ?? |
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oyais
India
7 Posts |
Posted - 08/10/2013 : 06:16:26 AM
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i have forwarded data on the given mail
@rlewis pls help with programming... i am not able to do it
oyais |
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oyais
India
7 Posts |
Posted - 08/12/2013 : 02:45:50 AM
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@Christyli,
have u checked my data and pls update me about the calculation of common area under the two curves.
oyais
oyais |
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Hideo Fujii
USA
1582 Posts |
Posted - 08/23/2013 : 4:35:42 PM
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Hi,
Here is what Greg has meant.
Col(E) is the Set Column Values' result of interpolated Y values based on the X dataset of the
second curve in Col(C). Its formula, "col(Y1)(col(X2))"uses a dataset(col(Y1)) as a function,
taking col(X2) as the argument.
(Note: You can make and use a separate X column with a range of your choice before this col(E).)
Also, see http://wiki.originlab.com/~originla/ltwiki/index.php?title=Script:Interpolation .
Col(F) is the Set Column Values' result of taking the lower values of col(D) vs. col(E) using min( ) function.
col(G) is the Integration result from col(F) (vs. col(C) as X).
Graph1 shows plots of col(B), col(D) and col(G). Col(G) plot has "Fill Area Under Curve" option.
Hope this has explained well.
--Hideo Fujii
OriginLab |
Edited by - Hideo Fujii on 08/23/2013 5:22:03 PM |
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misz_waza
Australia
1 Posts |
Posted - 11/06/2014 : 5:25:56 PM
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Hi Hideo and Originlab tech support,
I can't really get it the step that you did to find the area under the curve.Can you explain step by step?Attach is the graph that I want to find the area?I want to find the area for the black colour..
Hope you can help me.
Thanks a lot
waza |
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Hideo Fujii
USA
1582 Posts |
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lkb0221
China
497 Posts |
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Topic |
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claculation of overlap area under two curves