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taniasalgueiro
Portugal
13 Posts |
 Posted - 03/03/2014 : 08:52:29 AM
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Origin Ver. and Service Release (Select Help-->About Origin): 9
Operating System: Windows 7
Hi there!
I wanna know if there's possibible in a graphic like this: 
trace a tangent, knows when the 1st derivate is zero, and then intersect the tangent with the horizontal lines that initiates and finishes. Sorry my english, i hope you understant.
In pratical, i wanna a tangent that intersect with the minimum y and the maxim y. With is, I wanna know the range that y is different. It's an enthaphy graphic. I wanna know the fusion range and solidification range. It's a simple way to know this.
Thank you! |
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lkb0221
China
497 Posts |
Posted - 03/03/2014 : 10:27:47 AM
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Hi,
You can:
1). Use Differentiate gadget to get derivative curve.
2). Use Vertical Cursor gadget to find the corresponding point.
3). Use Tangent gadget to generate tangent line.
See my example below:
You can get Tangent gadget form the following webpage:
http://www.originlab.com/fileexchange/details.aspx?fid=153
Zheng
OriginLab |
Edited by - lkb0221 on 03/03/2014 10:28:34 AM |
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taniasalgueiro
Portugal
13 Posts |
Posted - 03/03/2014 : 12:29:53 PM
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I'm not sure, I'm following you. So, I know which the peak is, and I wanna that the tangent touch in that point. And then I wanna trace two horizontal lines. And then i wanna the area.
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taniasalgueiro
Portugal
13 Posts |
Posted - 03/03/2014 : 1:59:17 PM
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I pretend something like that:
the I wanna an horizontal line with minimum y and the the area of the triangule. Is it possible? |
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lkb0221
China
497 Posts |
Posted - 03/03/2014 : 2:12:20 PM
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Hi,
So actually you want to find the peak of 1st derivative, right? Which is where the 2nd derivative passes zero. And find the corresponding Y value on the original curve. Then calculate the Y range beyond/below this point.
All of the above can be done in the worksheet. Please see my example below, Graph1 is the data I used.
So you can:
1). Use "Analysis: Mathematics: Differentiate" to get 1st derivative curve.
2). Use "Analysis: Peaks and Baseline: Peak Analyzer" to find the maximum point of 1st derivative curve.
3). Use "Analysis: Mathematics: Interpolate/Extrapolate Y form X" to find the corresponding Y value. (The peak value was in "Peak_Centers1" worksheet, I copied it here.)
4). Then you will get the target Y value in col(E).
5). Use SCV to calculate the ranges ( col(F) and col(G) ).
Please email <tech@originlab.com> if you have further questions, for this might hard to explain through forum posts.
Zheng
Originlab |
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taniasalgueiro
Portugal
13 Posts |
Posted - 03/03/2014 : 4:32:57 PM
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Well, I have a data with heat specific and temperature.Then I integrated and i have enthalpy, which is the graphic I showed in topic.
With the specific heat graphic, I really know the peak fusion and solidification. What I need is the variation of temperatures of that, and the value of enthalpy, not just the curve. So, for this, I wanted to do a tangent line at the point we know that's the peak, and than make a triangle, with a baseline in y=0, and the area.
Hope i make myself clear. It's a difficult question to explain.
Thanks in advance. |
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lkb0221
China
497 Posts |
Posted - 03/03/2014 : 5:12:41 PM
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Hi,
I sent an email to your G-mail account, please check.
Zheng
OriginLab |
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Topic |
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Tangent And Intersect