function rw = writer(fh,matout);
% rw=write(fh,matout) Writes rw rows of matout to file specified by fh which
% is a Gauss data set either opened for append using openfa( ) or
% using the Gauss create command
global gaussfh;                              % gauss file handle info
if cols(matout) ~= gaussfh(fh,1);
   'error columns of passed matrix do not correspond to columns of';
   'gauss file handle';
end;
status=fseek(fh,0,1);                        % move file ptr to eof
netr=rows(matout)*cols(matout);              % number of elements to write
if gaussfh(fh,2)==1;
   precstr='uchar'; % assume unsigned character
elseif gaussfh(fh,2)==2;
   precstr='uint16'; % assumed unsigned integer 16 bit
elseif gaussfh(fh,2)==4;
   precstr='float32' % assume 32 bit floating
elseif gaussfh(fh,2)==8;
   precstr='float64' % assume 64 bit floating
end; 
rw=fwrite(fh,matout',precstr);
rw=rw/cols(matout); % since we want rows written
return;