iam getting error while iam debugging the code in matlab 2019, But it is excuting in matlab 2014 version.... Iwant this in MATLAB 2019 please help me

function varargout = mygui(varargin)
% MYGUI MATLAB code for mygui.fig
%      MYGUI, by itself, creates a new MYGUI or raises the existing
%      singleton*.
%
%      H = MYGUI returns the handle to a new MYGUI or the handle to
%      the existing singleton*.
%
%      MYGUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in MYGUI.M with the given input arguments.
%
%      MYGUI('Property','Value',...) creates a new MYGUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before mygui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to mygui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help mygui

% Last Modified by GUIDE v2.5 02-Mar-2019 16:47:03

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State=struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @mygui_OpeningFcn, ...
                   'gui_OutputFcn',  @mygui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
              % gui_State1 = struct2cell(gui_State);
              % gui_State= cell2mat(gui_State1);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before mygui is made visible.
function mygui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to mygui (see VARARGIN)

% Choose default command line output for mygui
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes mygui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = mygui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in image_read.
function image_read_Callback(hObject, eventdata, handles)
% hObject    handle to image_read (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global im_inp
im_inp=imread('greens.jpg');    % image to be transmitted and matlab code should be in same directory
axes(handles.axes1)
imshow(im_inp);
title('Original Image');


% --- Executes on button press in select_fading.
function select_fading_Callback(hObject, eventdata, handles)
% hObject    handle to select_fading (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of select_fadingc  
global im_inp tx_16qam input P_av
val=get(hObject,'Value');
N=numel(im_inp);
[LL,LH,HL,HH]=dwt2(im_inp,'haar');
var_ll=var(LL(:));
var_lh=var(LH(:));
var_hl=var(HL(:));
var_hh=var(HH(:));
in2=reshape(im_inp,N,1);
bin=de2bi(in2,'left-msb');
%% Serialization
input=reshape(bin',numel(bin),1);
len=length(input);
%%%%% padding zeroes to input CP addition%%%
z=len;
while(rem(z,2) || rem(z,4)|| rem(z,6))
    z=z+1;
    input(z,1)=0;
end
input=double(input);
h_16qam=qammod('M',16,'inputtype','bit');
y_16qam=modulate(h_16qam,input);
ifft_out_16qam=ifft(y_16qam);
SNR=menu('Select SNR Value','5','10','15');          % SNR in dB
SNR=SNR*5;
p=raylpdf(ifft_out_16qam,0.5);
solve('log(P_av)+(0.5/P_av)+log(p)==0','P_av')
P_av=ans;
for ii=1:4
    if ii<4
        y_distort(ii)=var_ll.^2+var_lh.^2+var_hl.^2+var_hh.^2+i*(128/12);
    else
        y_distort(ii)=i*128/12;
    end
end
x_distort=(0:5);


if (val==3)
    rayleighChan=comm.RayleighChannel(...
        'SampleRate',          1000,...
        'PathDelays',          [0 1.5e-4],...
        'AveragePathGains',    [2 3],...
        'NormalizePathGains',  true,...
        'MaximumDopplerShift', 30,...
        'DopplerSpectrum',     {doppler('Gaussian',0.06), doppler('Flat')},...
        'RandomStream',        'mt19937ar with seed',...
        'Seed',                22,...
        'PathGainsOutputPort', true);
    [ifft_0ut_16qam,SNR]=Step(rayleighChan,ifft_out_16qam,SNR);
    
    
end        
for j=6:15
    P_th=1/j;
    F=P_av.*P_th;
    prob(j,:)=1-exp(-1./F);
end
for k=1:numel(x_distort)
    P(k,:)=[4;x_distort(k)].*prob(k).^(4-x_distort(k)).*(1-prob(k)).^x_distort(k);
end

tx_16qam=awgn(ifft_out_16qam,SNR,'measured');
msgbox('Modulation DOne')    
% --- Executes on button press in rcv.
function rcv_Callback(hObject, eventdata, handles)
% hObject    handle to rcv (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global tx_16qam im_inp input y_distort
N=numel(im_inp);
k_16qam=fft(tx_16qam);
g_16qam=qamdemod('M',16,'outputtype','bit');
l_16qam=demodulate(g_16qam,k_16qam);
output_16qam=uint8(l_16qam);
%% Serial to Paraller
b2=reshape(output_16qam,8,N)';
%%binary to dec
dec_16qam=bi2de(b2,'left-msb');
y_distort=[31,18,17,12,-5];
len=length(input);
BER_16qam=biterr(input,l_16qam)/len;
im_16qam=reshape(dec_16qam(1:N),size(im_inp,1),size(im_inp,2),size(im_inp,3));
axes(handles.axes2);
imshow(uint8(im_16qam));title('16QAM');
SSIM_16qam=ssim(im_16qam,im_inp);
UQI=calculate_uqi(im_16qam,im_inp);
PSNR=psnr(im_16qam,im_inp)
fprintf('The BER=%f SSIM=%f UQI=%f PSNR=%f\n',BER_16qam,SSIM_16qam,UQI,PSNR)


function UQI=calculate_uqi(img1,img2)
global x_distort y_distort
block_size = 8;
N = block_size.^2;
sum2_filter = ones(block_size);
img1=im2double(rgb2gray(img1));
img2=im2double(rgb2gray(img2));
img1_sq   = img1.*img1;
img2_sq   = img2.*img2;
img12 = img1.*img2;

img1_sum   = filter2(sum2_filter, img1, 'valid');
img2_sum   = filter2(sum2_filter, img2, 'valid');
img1_sq_sum = filter2(sum2_filter, img1_sq, 'valid');
img2_sq_sum = filter2(sum2_filter, img2_sq, 'valid');
img12_sum = filter2(sum2_filter, img12, 'valid');

img12_sum_mul = img1_sum.*img2_sum;
img12_sq_sum_mul = img1_sum.*img1_sum + img2_sum.*img2_sum;
numerator = 4*(N*img12_sum - img12_sum_mul).*img12_sum_mul;
denominator1 = N*(img1_sq_sum + img2_sq_sum) - img12_sq_sum_mul;
denominator = denominator1.*img12_sq_sum_mul;
x_distort=0:4;
quality_map = ones(size(denominator));
index = (denominator1 == 0) & (img12_sq_sum_mul ~= 0);
quality_map(index) = 2*img12_sum_mul(index)./img12_sq_sum_mul(index);
index = (denominator ~= 0);
quality_map(index) = numerator(index)./denominator(index);
UQI = mean2(quality_map);


% --- Executes on button press in conditional_distort.
function conditional_distort_Callback(hObject, eventdata, handles)
% hObject    handle to conditional_distort (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global x_distort y_distort
bar(x_distort,y_distort)
xlabel('No of data vectors rcvd')
ylabel('Conditional Distortion')


% --- Executes on button press in datavector_loss.
function datavector_loss_Callback(hObject, eventdata, handles)
% hObject    handle to datavector_loss (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global P
P_th=6:15;
%axes(handles.axes2);
%cla
figure
plot(P_th,P(1,:),'b*-')
hold on
plot(P_th,P(2,:),'g*-')
plot(P_th,P(3,:),'r*-')
plot(P_th,P(4,:),'k*-')
plot(P_th,P(5,:),'y*-')
legend('P0','P1','P2','P3','P4')

error is

>> mygui

Error using qammod

Expected input number 1, X, to be one of these types:

double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64

Error in qammod>validateInput (line 284)

validateattributes(x, {'numeric'}, {'real','binary'}, mfilename, 'X', 1);

Error in qammod (line 95)

validateInput(x, M, bitInput, outputDataType);

Error in mygui>select_fading_Callback (line 117)

h_16qam=qammod('M',16,'inputtype','bit');

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in mygui (line 44)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)mygui('select_fading_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

[Rik]

I had a look at the qammod function documentation in both R2014a and R2019a, and I don't see why you would expect your syntax to work. The rest of the GUI is not relevant for this error, since it doesn't redefine this function.

[krishna kotha]

modem.qammod

in 2014 i used this function instead of qammod to excute code but in 2019 it says it is removed in 2014 i used this code

function varargout = mygui(varargin)
% MYGUI MATLAB code for mygui.fig
%      MYGUI, by itself, creates a new MYGUI or raises the existing
%      singleton*.
%
%      H = MYGUI returns the handle to a new MYGUI or the handle to
%      the existing singleton*.
%
%      MYGUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in MYGUI.M with the given input arguments.
%
%      MYGUI('Property','Value',...) creates a new MYGUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before mygui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to mygui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help mygui

% Last Modified by GUIDE v2.5 02-Mar-2019 16:47:03

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @mygui_OpeningFcn, ...
                   'gui_OutputFcn',  @mygui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before mygui is made visible.
function mygui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to mygui (see VARARGIN)

% Choose default command line output for mygui
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes mygui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = mygui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in image_read.
function image_read_Callback(hObject, eventdata, handles)
% hObject    handle to image_read (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global im_inp
im_inp=imread('greens.jpg');    % image to be transmitted and matlab code should be in same directory
axes(handles.axes1)
imshow(im_inp);
title('Original Image');


% --- Executes on button press in select_fading.
function select_fading_Callback(hObject, eventdata, handles)
% hObject    handle to select_fading (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of select_fadingc  
global im_inp tx_16qam input P_av
val=get(hObject,'Value');
N=numel(im_inp);
[LL,LH,HL,HH]=dwt2(im_inp,'haar');
var_ll=var(LL(:));
var_lh=var(LH(:));
var_hl=var(HL(:));
var_hh=var(HH(:));
in2=reshape(im_inp,N,1);
bin=de2bi(in2,'left-msb');
%% Serialization
input=reshape(bin',numel(bin),1);
len=length(input);
%%%%% padding zeroes to input CP addition%%%
z=len;
while(rem(z,2) || rem(z,4)|| rem(z,6))
    z=z+1;
    input(z,1)=0;
end
input=double(input);
h_16qam=modem.qammod('M',16,'inputtype','bit');
y_16qam=modulate(h_16qam,input);
ifft_out_16qam=ifft(y_16qam);
SNR=menu('Select SNR Value','5','10','15');          % SNR in dB
SNR=SNR*5;
p=raylpdf(ifft_out_16qam,0.5);
solve('log(P_av)+(0.5/P_av)+log(p)==0','P_av')
P_av=ans;
for ii=1:4
    if ii<4
        y_distort(ii)=var_ll.^2+var_lh.^2+var_hl.^2+var_hh.^2+i*(128/12);
    else
        y_distort(ii)=i*128/12;
    end
end
x_distort=(0:5);


if (val==3)
    rayleighChan=comm.RayleighChannel(...
        'SampleRate',          1000,...
        'PathDelays',          [0 1.5e-4],...
        'AveragePathGains',    [2 3],...
        'NormalizePathGains',  true,...
        'MaximumDopplerShift', 30,...
        'DopplerSpectrum',     {doppler('Gaussian',0.06), doppler('Flat')},...
        'RandomStream',        'mt19937ar with seed',...
        'Seed',                22,...
        'PathGainsOutputPort', true);
    [ifft_0ut_16qam,SNR]=Step(rayleighChan,ifft_out_16qam,SNR);
    
    
end        
for j=6:15
    P_th=1/j;
    F=P_av.*P_th;
    prob(j,:)=1-exp(-1./F);
end
for k=1:numel(x_distort)
    P(k,:)=[4;x_distort(k)].*prob(k).^(4-x_distort(k)).*(1-prob(k)).^x_distort(k);
end

tx_16qam=awgn(ifft_out_16qam,SNR,'measured');
msgbox('Modulation DOne')    
% --- Executes on button press in rcv.
function rcv_Callback(hObject, eventdata, handles)
% hObject    handle to rcv (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global tx_16qam im_inp input y_distort
N=numel(im_inp);
k_16qam=fft(tx_16qam);
g_16qam=modem.qamdemod('M',16,'outputtype','bit');
l_16qam=demodulate(g_16qam,k_16qam);
output_16qam=uint8(l_16qam);
%% Serial to Paraller
b2=reshape(output_16qam,8,N)';
%%binary to dec
dec_16qam=bi2de(b2,'left-msb');
y_distort=[31,18,17,12,-5];
len=length(input);
BER_16qam=biterr(input,l_16qam)/len;
im_16qam=reshape(dec_16qam(1:N),size(im_inp,1),size(im_inp,2),size(im_inp,3));
axes(handles.axes2);
imshow(uint8(im_16qam));title('16QAM');
SSIM_16qam=ssim(im_16qam,im_inp);
UQI=calculate_uqi(im_16qam,im_inp);
PSNR=psnr(im_16qam,im_inp)
fprintf('The BER=%f SSIM=%f UQI=%f PSNR=%f\n',BER_16qam,SSIM_16qam,UQI,PSNR)


function UQI=calculate_uqi(img1,img2)
global x_distort y_distort
block_size = 8;
N = block_size.^2;
sum2_filter = ones(block_size);
img1=im2double(rgb2gray(img1));
img2=im2double(rgb2gray(img2));
img1_sq   = img1.*img1;
img2_sq   = img2.*img2;
img12 = img1.*img2;

img1_sum   = filter2(sum2_filter, img1, 'valid');
img2_sum   = filter2(sum2_filter, img2, 'valid');
img1_sq_sum = filter2(sum2_filter, img1_sq, 'valid');
img2_sq_sum = filter2(sum2_filter, img2_sq, 'valid');
img12_sum = filter2(sum2_filter, img12, 'valid');

img12_sum_mul = img1_sum.*img2_sum;
img12_sq_sum_mul = img1_sum.*img1_sum + img2_sum.*img2_sum;
numerator = 4*(N*img12_sum - img12_sum_mul).*img12_sum_mul;
denominator1 = N*(img1_sq_sum + img2_sq_sum) - img12_sq_sum_mul;
denominator = denominator1.*img12_sq_sum_mul;
x_distort=0:4;
quality_map = ones(size(denominator));
index = (denominator1 == 0) & (img12_sq_sum_mul ~= 0);
quality_map(index) = 2*img12_sum_mul(index)./img12_sq_sum_mul(index);
index = (denominator ~= 0);
quality_map(index) = numerator(index)./denominator(index);
UQI = mean2(quality_map);


% --- Executes on button press in conditional_distort.
function conditional_distort_Callback(hObject, eventdata, handles)
% hObject    handle to conditional_distort (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global x_distort y_distort
bar(x_distort,y_distort)
xlabel('No of data vectors rcvd')
ylabel('Conditional Distortion')


% --- Executes on button press in datavector_loss.
function datavector_loss_Callback(hObject, eventdata, handles)
% hObject    handle to datavector_loss (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global P
P_th=6:15;
%axes(handles.axes2);
%cla
figure
plot(P_th,P(1,:),'b*-')
hold on
plot(P_th,P(2,:),'g*-')
plot(P_th,P(3,:),'r*-')
plot(P_th,P(4,:),'k*-')
plot(P_th,P(5,:),'y*-')
legend('P0','P1','P2','P3','P4')

and iam getting these type of error

>> mygui

Error using modem.qammod (line 82)

MODEM.QAMMOD has been removed. Use QAMMOD instead.

Error in mygui>select_fading_Callback (line 115)

h_16qam=modem.qammod('M',16,'inputtype','bit');

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in mygui (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)mygui('select_fading_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

>>

what should i do now....?

[krishna kotha]

I don't see why you would expect your syntax to work

mean i din't understand.....???

what shoud i do i need solution. any changes can i do.....?

Answer 1

[Rik]

There are only two relevant lines from your enormous blocks of code (that you didn't format yourself):

%initial post:
h_16qam=qammod('M',16,'inputtype','bit');
%second post:
h_16qam=modem.qammod('M',16,'inputtype','bit');

Did you read the documentation? It explains the syntax that you can use for that function. I can't find explicit documentation for modem.qammod, but for the qammod function you can find the syntax in the doc pages I linked. Judging by what I could find, I suspect the correct syntax in your case should be this:

%remove these two lines:
h_16qam=modem.qammod('M',16,'inputtype','bit');
y_16qam=modulate(h_16qam,input);

%replace by:
y_16qam=qammod(input,16,'inputtype','bit');

I'm not entire sure if you need to change something about the input variable.

[krishna kotha]

h_16qam=modem.qammod('M',16,'inputtype','bit');

in 2014 documentation it is mentioned that as "M M-ary value. Default is 16." i found in

https://in.mathworks.com/help/releases/R2012a/toolbox/comm/ref/modem.qammod.html

but in 2019 it is not there i found in 2012a documentation

[Steven Lord]

As stated in the release notes for Communcation Toolbox the modem.qammod function has been removed. Replace it with a call to qammod.

If you need this code to run in both release R2012a and release R2019a, you can wrap the modem.qammod call in a try / catch block or you can detect whether you're using a release that includes the modem package with verLessThan.

[Rik]

@Stephen, I searched the RN as well, but was unable to find this. Now I found out that I can't rely on the search tool, but I should check each product separately (the MATLAB search option apparently only being for the base product). Thank you for revealing this to me.

[krishna kotha]

ok i want to excute in 2019 so any modifications is possible.

because iam confusing with errors.....!!!!

[Steven Lord]

Rik: Searching the Release Notes for "qammod" found three hits for me, the first of which is the Communications Toolbox RNs. If I change that to "modem.qammod" the Communications Toolbox notes are the only hit.

krishna kotha: If you want to run this code in R2019a, replace modem.qammod calls with calls to qammod. I don't know offhand if the syntax for the two is the same or if you'll need to adjust how you call the function slightly.

[krishna kotha]

i have done it. i excuted code with qammod in r2019b but the error is

>> mygui

Error using solve>getEqns (line 418)
List of equations must not be empty.

Error in solve (line 226)
[eqns,vars,options] = getEqns(varargin{:});

Error in mygui>select_fading_Callback (line 123)
solve('log(P_av)+(0.5/P_av)+log(p)==0','P_av');

Error in gui_mainfcn (line 95)
        feval(varargin{:});

Error in mygui (line 44)
    gui_mainfcn(gui_State, varargin{:});

Error in
matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)mygui('select_fading_Callback',hObject,eventdata,guidata(hObject)) 
Error while evaluating UIControl Callback.

>>

syntax is does not matching with previous one

h_16qam=modem.qammod('M',16,'inputtype','bit');

y_16qam=qammod(input,16,'inputtype','bit');

and modified code is

Edit Rik: code moved to attachment for readability of the thread.

[Rik]

You call the function solve (R2019a doc). That has a warning:

Character vector inputs have been removed. 
Instead, use syms to declare variables and replace inputs 
such as solve('2*x == 1','x') with solve(2*x == 1,x).

So let's do that. Since the R2012a version of solve also supports sym inputs, we don't need to worry about any incompatiblity.

%don't use globals
%use other methods of sharing data between callback (like e.g. guidata)
syms P_av
P_av_result=solve(log(P_av)+(0.5/P_av)+log(p)==0,P_av);
%don't use ans, just store the result