<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />Hi! I have scripted a simple moving average, but I need to work on the data (calculate the slope variation), so I want to save it to a data table. But how do I script that?
Ideas on how to calculate the slope are also welcome! What I'm thinking is to simply take the derivative as a lag (ds/dt=(time-lag(time,x)) / (position-lag(position,x))
Jim, thanks, that did the trick
Meanwhile I calculated manually, but will now use Jim's solution. And JoseGL, I used the following formula that you also should be able to use. You can use Lag(:variable,index) to indicate row index. it is much more flexible this way, because you can change the counter n to any desired value.
In my data, I often need to calculate the slope of a small section of rows that repeats every 200 rows in files with > 500K rows, and this is the way I usually do it:
1) Add an artificial marker* [e.g.,0 through 200] to the "row series" using a sequence
*I call this variable measurement time
2) Set the length of the X and Y averages for the slope formula
3) Use an IF statement to estimate the slope of the range or rows I want
4) [In my data] I correct all measurements with the slope
This is the script I use [heavily hard coded, but gets the job done for me ^_^ ]
Y_Mean = Mean( :MA_T1[Row()], :MA_T1[Row() + 1], :MA_T1[Row() + 2], :MA_T1[Row() + 3], :MA_T1[Row() + 4], :MA_T1[Row() + 5], :MA_T1[Row() + 6], :MA_T1[Row() + 7], :MA_T1[Row() + 8], :MA_T1[Row() + 9], :MA_T1[Row() + 10], :MA_T1[Row() + 11], :MA_T1[Row() + 12], :MA_T1[Row() + 13], :MA_T1[Row() + 14] ); X_Mean = Mean( :Measurement time[Row()], :Measurement time[Row() + 1], :Measurement time[Row() + 2], :Measurement time[Row() + 3], :Measurement time[Row() + 4], :Measurement time[Row() + 5], :Measurement time[Row() + 6], :Measurement time[Row() + 7], :Measurement time[Row() + 8], :Measurement time[Row() + 9], :Measurement time[Row() + 10], :Measurement time[Row() + 11], :Measurement time[Row() + 12], :Measurement time[Row() + 13], :Measurement time[Row() + 14] ); If( :Measurement time == 1, Slope = ((:Measurement time[Row()] - X_Mean) * (:MA_T1[Row()] - Y_Mean) + (:Measurement time[Row() + 1] - X_Mean) * (:MA_T1[Row() + 1] - Y_Mean) + (:Measurement time[Row() + 2] - X_Mean) * (:MA_T1[Row() + 2] - Y_Mean) + (:Measurement time[Row() + 3] - X_Mean) * (:MA_T1[Row() + 3] - Y_Mean) + (:Measurement time[Row() + 4] - X_Mean) * (:MA_T1[Row() + 4] - Y_Mean) + (:Measurement time[Row() + 5] - X_Mean) * (:MA_T1[Row() + 5] - Y_Mean) + (:Measurement time[Row() + 6] - X_Mean) * (:MA_T1[Row() + 6] - Y_Mean) + ( :Measurement time[Row() + 7] - X_Mean) * (:MA_T1[Row() + 7] - Y_Mean) + (:Measurement time[Row() + 8] - X_Mean) * (:MA_T1[Row() + 8 ] - Y_Mean) + (:Measurement time[Row() + 9] - X_Mean) * (:MA_T1[Row() + 9] - Y_Mean) + (:Measurement time[Row() + 10] - X_Mean) * ( :MA_T1[Row() + 10] - Y_Mean) + (:Measurement time[Row() + 11] - X_Mean) * (:MA_T1[Row() + 11] - Y_Mean) + (:Measurement time[Row() + 12] - X_Mean) * (:MA_T1[Row() + 12] - Y_Mean) + (:Measurement time[Row() + 13] - X_Mean) * (:MA_T1[Row() + 13] - Y_Mean) + ( :Measurement time[Row() + 14] - X_Mean) * (:MA_T1[Row() + 14] - Y_Mean)) / ((:Measurement time[Row()] - X_Mean) ^ 2 + ( :Measurement time[Row() + 1] - X_Mean) ^ 2 + (:Measurement time[Row() + 2] - X_Mean) ^ 2 + (:Measurement time[Row() + 3] - X_Mean) ^ 2 + (:Measurement time[Row() + 4] - X_Mean ^ 2) + (:Measurement time[Row() + 5] - X_Mean) ^ 2 + (:Measurement time[Row() + 6] -X_Mean) ^ 2 + (:Measurement time[Row() + 7] - X_Mean) ^ 2 + (:Measurement time[Row() + 8] - X_Mean) ^ 2 + (:Measurement time[Row() + 9] - X_Mean) ^ 2 + (:Measurement time[Row() + 10] - X_Mean) ^ 2 + (:Measurement time[Row() + 11] - X_Mean) ^ 2 + ( :Measurement time[Row() + 12] - X_Mean) ^ 2 + (:Measurement time[Row() + 13] - X_Mean) ^ 2 + (:Measurement time[Row() + 14] -X_Mean) ^ 2) ); If( :Measurement time < 1, :MA_T1, :MA_T1 - Slope * :Measurement time );)
Hope this helps,
And if someone know how to do do this please let me know:
[i.e., subscript the [user]-given name of a variable without having to use the actual name of the variable]
-JoseGL
Here is a simple example taken from the Help==>Scripting Index, for the Time Series Object that illustrates how to save the simple moving averages to a data table in a script.
Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Stock Prices.jmp" );
obj = Time Series(
Y(:Close ),
Simple
Moving Average( Add Model( 5 ) )
);
resultdt = obj <<
Simple Moving Average( Save to Data Table );
I won't venture an opinion on the calculation of the slope.
