Showing results for 
Search instead for 
Do you mean 
Reply

Test Lab Time Signal Calculator: Can a 6th Order Polynomial be used

The below 6th polynomial was generated in .xls. can it be applied to time date within the Test Lab Time Signal Calculator

=0.00000000008*B31^3 - 0.0000002*B31^2 + 0.0011*B31 - 0.7826

 

3 REPLIES

Re: Test Lab Time Signal Calculator: Can a 6th Order Polynomial be used

[ Edited ]

Hello, I'm not exactly sure what you are asking, so I will try to answer it two ways:

 

1)  With the correct header information you can use the Excel Data Driver to import that curve from Excel and use in the Time Signal Calculator, as a Derived Channel and in the Conditioning Toolbar on the Navigator via User Defined Weighting.  In the Time Signal Calculator you could then use the "B"  button to browse to the Data Block and it will be assigned to B1.  You can then use B1 in formulas such as CH1*B1.

pic1.jpg

 

2)  If you want to use that exact formula in the Time Signal Calculator, you cannot directly without tricking the units.  For example, with an acceleration channel the formula would yield g^3 - g^2+g - Constant and we cannot add those different units together.  This would cause a units error and could not be calculated:

 

0.00000000008*CH5^3- 0.0000002*ch5^2+0.0011*CH5-0.7826[g]

 

You could force the formula to work via:

(0.00000000008*CH5^3)[g]- (0.0000002*ch5^2)[g]+0.0011*CH5-0.7826[g]

 

That would add all the units together and result in g as the unit.  You could also place [g] around the third term but it is not needed if the channel is already in "g" units.

 

 

 

Re: Test Lab Time Signal Calculator: Can a 6th Order Polynomial be used

Kevin,

Thank you for the helpSmiley Happy. Attached is what I ended up with in Test Lab and the same time data calculated in .xls

 

Re: Test Lab Time Signal Calculator: Can a 6th Order Polynomial be used

Is that close enough for you?  Seems like a rounding problem somewhere but they look close.

 

You can also save steps by using [g/s] in your formula or whatever unit you want:

 

(0.00000000008*CH5^3)[g/s]- (0.0000002*ch5^2)[g/s]+(0.0011*CH5)[g/s]-0.7826[g/s]