How are the coefficents of plot Correlations Calculated
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Products:
Aspen DMC3
Last Updated:
05-Jan-2022
Last Updated:
05-Jan-2022
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Article ID:
000099410
Article ID:
000099410
Primary Subject:
Problem Statement
This Solution Frames how DMC3 Builder determines how many correlation coefficients to plot after running a case?
Solution
The MV Cross-Correlation plot reflects the correlation between two MVs over a time horizon window. A maximum value (between 0-1.0) at time t=0 shows the strongest correlation between the two MVs.
By default, the Scale of the correlation plots cannot be changed, and the Y-axis shows a scale between -1 and 1.
For this kind of plot DMC3 uses an equation to calculate the default number of correlation coefficients:
Number of Corr-Coeffs = TTSS x Samples/min; For example:
(1) Sampling = 15 Sec, TTSS=30 min, then NCC = 30 x 4 = 120 (for one-side), the display window will be -120 to +120;
(2) Sampling = 60 sec, TTSS=90 min, then NCC = 90 x 1 = 90, the correlation plot window will be -90 to +90.
Keywords
DMC3, Plot Correlations