Programmer Guide/Command Reference/EVAL/wsum: Difference between revisions

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Calculate the weighted sum over one or more user-defined extents of a function <var>y = f(x)</var>. Depending on the number of extents, the result of the function is a vector or a scalar.
Calculate the weighted sum over one or more user-defined extents of a function <var>y = f(x)</var>. Depending on the number of extents, the result of the function is a vector or a scalar.

Revision as of 13:19, 8 April 2011

Calculate the weighted sum over one or more user-defined extents of a function y = f(x). Depending on the number of extents, the result of the function is a vector or a scalar.

Usage
wsum(x, y, w, s, us, os, n)
sum(x, y, w, s, uv, ov)
sum(x, y, w, s, rv)
sum(x, y, w, s, rm)
x, y
the x- and y-data vector; y[i] = f(x[i])
wdefines the type of the weighting function
{class="keinrahmen"

|w=0 ||no weight (rectangle) |- |w=1 ||triangle |- |w=2 ||hanning window |- |w=2 ||hamming window |}

sif this argument is set to 1 the sum of each extent is normalized (scaled by 1/sum(weights)), otherwise not
Note: an extent is defined by the x-range {xmin, xmax} and not by the indices!
us, os, n
us is the lowest x-value, os the highest and n the number of extents. All three arguments are scalars. Every pair {'us'+d*k, us+d*(k+1)} (with: d=(os-us)/n, k=0..n-1) defines an extent to sum.
uv, ov
Every pair {uv[k], ov[k]} (with k=0..nrow(uv)-1) defines an extent to sum. Both arguments must be vectors with same length.
rv
Every pair {rv[k], rv[k+1]} (with k=0..nrow(rv)-2) defines an extent to sum. The argument must be vector.
rm
Every pair {rm[k,0], rm[k,1]} (with k=0..nrow(rm)-1) defines an extent to sum. The argument must be matrix with 2 columns.
Result
The result r is a scalar or a vector. Each element ri is the sum of weighted the y values over the i-th extent {xmini, xmax<sub}.
See also
sum, hist

<function list>

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