Neural Network Toolbox™

Process matrices by removing rows with constant values

Syntax

• [Y,PS] = removeconstantrows(max_range)
  [Y,PS] = removeconstantrows(X,FP)
  Y = removeconstantrows('apply',X,PS)
  X = removeconstantrows('reverse',Y,PS)
  dx_dy = removeconstantrows('dx',X,Y,PS)
  dx_dy = removeconstantrows('dx',X,[],PS)
  name = removeconstantrows('name');
  FP = removeconstantrows('pdefaults');
  names = removeconstantrows('pnames');
  removeconstantrows('pcheck',FP);
  

Description

removeconstantrows processes matrices by removing rows with constant values.

removeconstantrows(X,max_range) takes X and an optional parameter,

X	Single N x Q matrix or a 1 x TS row cell array of N x Q matrices
max_range	Maximum range of values for row to be removed (default is 0)

and returns

Y	Each M x Q matrix with N - M rows deleted (optional)
PS	Process settings that allow consistent processing of values

removeconstantrows(X,FP) takes parameters as a struct: FP.max_range.

removeconstantrows('apply',X,PS) returns Y, given X and settings PS.

removeconstantrows('reverse',Y,PS) returns X, given Y and settings PS.

removeconstantrows('dx',X,Y,PS) returns the M x N x Q derivative of Y with respect to X.

removeconstantrows('dx',X,[],PS) returns the derivative, less efficiently.

removeconstantrows('name') returns the name of this process method.

removeconstantrows('pdefaults') returns the default process parameter structure.

removeconstantrows('pdesc') returns the process parameter descriptions.

removeconstantrows('pcheck',FP) throws an error if any parameter is illegal.

Examples

Here is how to format a matrix so that the rows with constant values are removed.

• x1 = [1 2 4; 1 1 1; 3 2 2; 0 0 0]
  [y1,PS] = removeconstantrows(x1)
  

Next, apply the same processing settings to new values.

• x2 = [5 2 3; 1 1 1; 6 7 3; 0 0 0]
  y2 = removeconstantrows('apply',x2,PS)
  

Reverse the processing of y1 to get x1 again.

• x1_again = removeconstantrows('reverse',y1,PS)
  

See Also

fixunknowns, mapminmax, mapstd, processpca

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