sum
sum (waveName [, x1, x2])
The sum function returns the sum of the wave elements for points from x=x1 to x=x2.
Details
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 x1 and x2 are not specified, they default to -inf and +inf, respectively.
If the points nearest to x1 or x2 are not within the point range of 0 to numpnts(waveName )-1, sum limits them to the nearest of point 0 or point numpnts(waveName)-1.
If any values in the point range are NaN, sum returns NaN.
sum also accepts text waves. Each text element that can be converted to a number is summed as that number; a text wave containing no numeric elements evaluates to 0. For example:
Make/T/O tw = {"1", "10"}
Print sum(tw) // numeric text is converted and summed
11
Make/T/O twNoNum = {"abcd", "efgh"}
Print sum(twNoNum) // no elements convert to a number
0
Wave reference and data folder reference waves are not a supported input to sum, but no error is raised; sum simply returns 0 for them.
Examples
Make/O/N=100 data; SetScale/I x 0,Pi,data
data=sin(x)
Print sum(data,0,Pi) // the entire point range, and no more
Print sum(data) // same as -infinity to +infinity
Print sum(data,Inf,-Inf) // +infinity to -infinity
The following is printed to the history area:
Print sum(data,0,Pi) // the entire point range, and no more
63.0201
Print sum(data) // same as -infinity to +infinity
63.0201
Print sum(data,Inf,-Inf) // +infinity to -infinity
63.0201