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mean

mean (waveName [, x1, x2])​

The mean function returns the arithmetic mean of the wave for points from x=x1 to x=x2.

Details​

If x1 and x2 are not specified, they default to -INF and +INF, respectively.

The wave values from x1 to x2 are summed, and the result divided by the number of points in the range.

The X scaling of the wave is used only to locate the points nearest to x=x1 and x=x2. To use point indexing, replace x1 with "pnt2x(waveName,pointNumber1 )", and a similar expression for x2.

If the points nearest to x1 or x2 are not within the point range of 0 to numpnts(waveName )-1, mean limits them to the nearest of point 0 or point numpnts(waveName)-1.

If any values in the point range are NaN, mean returns NaN.

The function returns NaN if the input wave has zero points.

Unlike the area function, reversing the order of x1 and x2 does not change the sign of the returned value.

The mean function is not multidimensional aware. See Multidimensional Waves, particularly Analysis on Multidimensional Waves for details.

Examples​

Make/O/N=100 data; SetScale/I x 0,Pi,data
data=sin(x)
Print mean(data,0,Pi)     // the entire point range, and no more
Print mean(data)          // same as -infinity to +infinity
Print mean(data,Inf,-Inf) // +infinity to -infinity

The following is printed to the history area:

Print mean(data,0,Pi)     // the entire point range, and no more
  0.630201
Print mean(data)          // same as -infinity to +infinity
  0.630201
Print mean(data,Inf,-Inf) // +infinity to -infinity
  0.630201

See Also​

Variance, WaveStats, median, APMath

The figure "Comparison of area, faverage and mean functions over interval (12.75,13.32)", in the Details section of faverage.