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jamiva

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09-30-2014 11:18 AM

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The "Derivative x(t).VI" works when I select any method but "4th Order Central" using the default Inital and Final Conditions. The 4th Order produces an:

error -2006 "Analysis: The number of samples must be >= 2."

The number of samples is 1000. The VI also produces the same error if I provide a data array to the Initial and Final Condition rather than using the default values. Am I doing something wrong? Is it a bug?

09-30-2014 11:22 AM

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I'm using LabVIEW 2014 Version 14.0.f1 (32-bit)

GerdW

Knight of NI

09-30-2014 11:23 AM

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Hi jarniva,

please read the help for the derivative function. It mentions some boundary conditions for the "4th order" calculation you need to supply!

Best regards,

GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO

GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO

09-30-2014 11:32 AM

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GerdW

Knight of NI

10-01-2014 01:50 AM - edited 10-01-2014 01:52 AM

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Hi jamiva,

to quote the LabVIEW help for Derivative:

Initial Condition: If method is 4th Order Central, the VI uses the first two elements in Initial Condition to calculate the derivative. The default is [0].

Final Condition: If method is 4th Order Central, the VI uses the first two elements in Final Condition to calculate the derivative. The default is [0].

Again: **Did you read the help for that function?** Did you read all of the help? Do you understand what it says?

Best regards,

GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO

GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO