The module "cummean" of the Mastrave modelling library
Copyright © 2005,2006,2007,2008,2009,2010,2011 Daniele de Rigo
The file cummean.m is part of Mastrave.
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answer = cummean( values , dim =  , mode = 'a' )
Utility to extend the function mean(.) providing cumulative means of the elements of the array values along a given dimension dim .
values ::numeric:: Vector, matrix or multi-dimensional array of numbers. dim ::scalar_index|empty:: Scalar positive integer representing the dimension along which the cumulative means have to be computed. If dim is an empty array  , the dimension is the first non-singleton dimension. In case values is a vector, this definition means that the default dimension is the one along which the elements of the vector values are aligned. If omitted, the default value is . mode ::string:: String declaring the kind of mean to be computed. If omitted, its default value is: 'a'. Valid modes are: mode │ meaning ─────────────────┼────────────────────────────────── 'a' │ Compute the ordinary arithmetic '--arithmetic' │ mean. ─────────────────┼────────────────────────────────── 'g' │ Compute the geometric mean. '--geometric' │ ─────────────────┼────────────────────────────────── 'h' │ Compute the harmonic mean. '--harmonic' │
% Basic usage % Vectors: m = ceil( rand(1,7)* 100 ) cm = cummean( m ) assert( cm(end) == mean(m) ) % Matrices: m = ceil( rand(5,7)* 100 ) cm = cummean( m ) assert( cm(end,:) == mean(m) ) % Passing a custom dimension cm = cummean( m , 2 ) assert( cm(:,end) == mean(m,2) ) % Dealing with multi-dimensional arrays m = ceil( rand(5,7,3)* 100 ) cm = cummean( m ) cm = cummean( m ,  ) assert( cm(end,:,:) == mean(m) ) cm = cummean( m , 3 ) assert( cm(:,:,end) == mean(m,3) ) % Passing the kind of mean to be computed cm = cummean( m , , '--arithmetic' ) cm = cummean( m , , 'a' ) assert( cm(end,:,:) == mean(m) ) % Geometric mean cm = cummean( m , , '--geometric' ) cm = cummean( m , , 'g' ) assert( cm(end,:,:) == prod(m,1).^(1/size(m,1)) ) cm = cummean( m , 2, 'g' ) assert( cm(:,end,:) == prod(m,2).^(1/size(m,2)) ) % Harmonic mean cm = cummean( m , , '--harmonic' ) cm = cummean( m , , 'h' ) assert( cm(end,:,:) == size(m,1)./sum(1./m,1) ) cm = cummean( m , 3, '--harmonic' ) assert( cm(:,:,end) == size(m,3)./sum(1./m,3) )
Memory requirements: O( numel( values ) ) See also: cumstd, cumvar, cumsumsq, groupfun Keywords: cumulative operators, scan Version: 0.4.3
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