Bug sur la fonction "Linear Fit" entre LW 8.0 et LW 2009
Bonjour,
nous rencontrons des différences sur le résultat de la fonction LINEAR FIT.vi (avec méthode bisquare)
Le même programme, un compilé sous LabVIEW 8.0 et l'autre sous LabVIEW 2009, donne des résultats différents.
Je ne trouve pas les corrections qui ont pu être apportées sur cette fonction entre les différentes versions de LabVIEW.
Comment être certain que la fonction donne de bons résultats ? Celle sous LabVIEW 8.0 est-elle correcte ?
Pour info, le résultat sous Lw 2014 est le même que sous LabVIEW 2009.
Merci
Sorry for the delay.
I added two sreenshots with the same function and the same datas: the first example runs on LW8.0 and the 2nd runs on LW2014.
We encounter differences on results (slope, interception ... etc)
Thank you for your help
Attachments:
RegLin_8.0.JPG 132 KB
RegLin_2014.jpg 144 KB
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Stuck againBrein wrote:
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Linear fit between two cursors from a signal from a NI-instruments via DAQ-Assistant
Hi !
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Go to Solution.
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I am trying use Linear Fit to made the best fit of temperature acquisition, but during the acquisition i acquire some NaN data.
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Brazil
Solved!
Go to Solution.
Attachments:
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The LV Help File is your friend, learn to use it. It gets lonely if you don't look in on it once in a while.
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To err is human, but to really foul it up requires a computer.
The optimist believes we are in the best of all possible worlds - the pessimist fears this is true.
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La lecture d'un DVD du commerce sur la fonction disque distant (PC) à partir d'un Mac Mini indique l'erreur -70025. Cette erreur a t-elle été résolue ?
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Weight values in weighted linear fit
I am using Labview 8.5, which has the weighted linear fit vi.
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I can't tell just by reading the help or looking online.
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Go to Solution.Prior to LabVIEW 8.0, there was a "standard deviation" input instead of a weight input for the nonlinear fit function, but internally the code was basically the same (It was immediately converted to a weight internally).
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Since it is mathematically very simple to translate an standard deviation into a weight, you can do that easily yourself.
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Hello Dahl
Do you mean like Upper Bound and Lower Bound output terminals of NI_Gmath.lvlib::Nonlineat Curve fir intervals.vi?
Message Edited by Eirikur on 01-09-2008 01:25 PM
Regards,
Eirikur Runarsson
Platinum Applications Engineer
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Hello,
I have to find the best straight line in a x-y measurement array.
The "Linear Fit.vi" uses a linear regression method normal to the x-Axes which leads to bad results if the sollution would be near a vertical straight line.
e.g.: with a Pair of measurement points with:
1.: x=0 Y=+1
2.: x=0 Y=-1
I would like to get a straigth vertical line (x=0, k=inf or something which represents this), the Linear Fit.vi's result is NaN
Does someone know where to find a vi for this?
Thank you for any comments.
Greetings
Mario HirthMario Hirth wrote:
Since I use the residuum of the linear fitting to evaluate the measurement (which should represent a straight line, but I dont know in which direction), I have to be mathematically correct.
I also had a solution by iteration with: "find slope" => "turn measurement data into x-axis according to slope" => start again with finding slope => do this about 5 times etc...
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What is the error in x and y for each data point?
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