function inoutsig = gaindb(inoutsig,gn,varargin)
%GAINDB Increase/decrease level of signal
% Usage: outsig = gaindb(insig,gn);
%
% GAINDB(insig,gn) increases the energy level of the signal by gn*
% dB.
%
% If gn is a scalar, the whole input signal is scaled.
%
% If gn is a vector, each column is scaled by the entries in
% gn. The length of gn must match the number of columns.
%
% GAINDB(insig,gn,dim) scales the signal along dimension dim.
%
% See also: rms
%
% Url: http://ltfat.github.io/doc/sigproc/gaindb.html
% Copyright (C) 2005-2023 Peter L. Soendergaard <peter@sonderport.dk> and others.
% This file is part of LTFAT version 2.6.0
%
% This program is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program. If not, see <http://www.gnu.org/licenses/>.
% AUTHOR: Peter L. Søndergaard, 2009
% ------ Checking of input parameters ---------
if nargin<2
error('%s: Too few input parameters.',upper(mfilename));
end;
if ~isnumeric(inoutsig)
error('%s: insig must be numeric.',upper(mfilename));
end;
if ~isnumeric(gn)
error('%s: gn must be numeric.',upper(mfilename));
end;
definput.keyvals.dim=[];
[flags,kv]=ltfatarghelper({'dim'},definput,varargin);
% ------ Computation --------------------------
if isscalar(gn)
inoutsig = inoutsig*10^(gn/20);
else
if isvector(gn)
M=length(gn);
[inoutsig,L,Ls,W,dim,permutedsize,order]=...
assert_sigreshape_pre(inoutsig,[],kv.dim,upper(mfilename));
if M~=W
error('%s: Length of gn and signal size must match.',upper(mfilename));
end;
for ii=1:W
inoutsig(:,ii)=inoutsig(:,ii)*10^(gn(ii)/20);
end;
inoutsig=assert_sigreshape_post(inoutsig,kv.dim,permutedsize,order);
else
if ~isnumeric(gn)
error('%s: gn must be a scalar or vector.',upper(mfilename));
end;
end;
end;