Output argument 'PreCharge' is not assigned on some execution paths

Hello,

I have a system in Simulink and I am getting the error;

"Output argument 'PreCharge' is not assigned on some execution paths"

Basically, when output signal PreCharge = 0, Upd1 = 1 and Simulink goes through the code in the function block. When PreCharge is 1, Upd1 = 0 and the code is therefore ignored for the rest of the simulation. I understand the error, because PreCharge is not declared outside of the if statement. However, I can't initialize the block outside of the if statement without it reiniatializing everytime it goes through the code. So I created a Base Workspace variable PreCharge with initial value = 0. I resolved the signal but I still get the error. The only way I can get it to work is to make it a global variable and I'm trying to avoid that.

My MatLAB Function block has the following code;

function [PreCharge,Red1,Yel]  = CheckList(PSto,T,WFt,LoadR,ChargeEn,SCD,WiFiCommSig,EPOR,clk,Upd1)
.
.
. 
    if Upd1 == 1
        disp('Check');
        if clk > Update1 + 0.1
            if WiFiCommSig == 0
                WiFiLost = WiFiLost + clk - Update1;
            else
                WiFiLost = 0;
            end
            Update1 = clk;       
            if WiFiCommSig == 0 && WiFiLost > WFt
                Check = 0;
                disp('No Wireless Communication')
            end
            if  Check == 1 && PS == PSto && clk > T;
                PreCharge = double(1);
            elseif Check == 0;
                disp('Fault')
                Red1 = 1;
            else
                disp('Updating')
            end
            InI = PS / LoadR;
        end
    end
end

[Kaustubha Govind]

Why not assign PreCharge to the desired value in the elseif and else blocks? Does that resolve the error?

[Nicholas]

Thank you for responding! I added else statements to each level of if statements and the error does go away but I put a display block on the output signal PreCharge and it does not change from zero even though at the breakpoint stepping through you can see PreCharge value change from 0 to 1. Once PreCharge = 1, I have it output from the function block to a compare to zero block set to > 0 . That signal then goes to the enable of an enabled subsystem. So when it goes to 1, the subsystem has a constant 0 being sent to an output which is used as the input for Upd1.

[dpb]

Would have to see the modified code and the other logic to tell...if the function is called and executing the

PreCharge = double(1);

(which, by the way, the double() there is superfluous, just use

PreCharge = 1;

)

then there must be some other cause/path that is clearing it later.

There's not a clear enough description in the verbiage that I can really follow the desired flowpath sufficiently to have an actual firm patch.

[Nicholas]

Thank you for replying. The function is not being used anywhere else. I tested the Compare to Zero and enabled subsystem combo of blocks I mentioned earlier in a small system and they work the way I want so I don't believe they are the problem. Here is an updated look at my code. I stepped through it and once PreCharge = 1 the green arrow skips ahead elsewhere in the simulation. But PreCharge never changes and Upd1 is therefore never set to 0.

function [PreCharge,Red1,Yel]  = CheckList(PSto,T,WFt,LoadR,ChargeEn,SCD,WiFiCommSig,EPOR,clk,Upd1)
    if Upd1 == 1
        disp('Check');
        if clk > Update1 + 0.1
            if WiFiCommSig == 0
                WiFiLost = WiFiLost + clk - Update1;
            else
                WiFiLost = 0;
            end
            Update1 = clk;       
            if WiFiCommSig == 0 && WiFiLost > WFt
                Check = 0;
                disp('No Wireless Communication')
            end
            if  Check == 1 && PS == PSto && clk > T;
                PreCharge = 1;
            elseif Check == 0;
                disp('Fault')
                Red1 = 1;
                PreCharge = 0;
            else
                disp('Updating')
                PreCharge = 0;
            end
        else
            PreCharge = 0;
        end
    else
        PreCharge = 1;
    end
end

[dpb]

Well, there's nothing in the code that will change Upd1 (and it isn't returned if there were) so that's the part that isn't shown well enough to know what you expect to change it and why that isn't happening as you think it should.

One thing I do note in your function is that you have a logic test on

if  Check == 1 && PS == PSto && clk > T;

but there's no path in the code that will ever set Check=1 unless it's GLOBAL.

Again, w/o a better overall picture of what you're trying to do can't really give an actual solution/suggestion. But, there's a logic flaw somewhere...

Answer 1

[Nicholas]

Sorry, I removed a large portion of the code to simplify it on here. Check is actually declared earlier in the function block. I believe I figured out the problem though. I think there was something wrong with the variable execution rate. After adding in a configuration from an old project it worked fine. Thank you both for trying to help.

[dpb]

Yes, clearly the problem was something not shown...a difficulty especially w/ Simulink owing to the model structure not lending itself to posting as is code.

Glad you did find/resolve it...

Answer 2

[Heawa Mehmandoust]

function [overall_snr, segmental_snr,segSNR] = Signal_to_Noise_Ratio(Speech, Enhanced_speech,sample_rate)

% ---------------------------------------------------------------------- % Check the length of the clean and processed speech. Must be the same. % ----------------------------------------------------------------------

clean_length = length(Speech); Enhanced_length = length(Enhanced_speech);

if (clean_length ~= Enhanced_length) disp('Error: Both Speech Files must be same length.'); return end

% ---------------------------------------------------------------------- % Scale both clean speech and processed speech to have same dynamic % range. Also remove DC component from each signal % ----------------------------------------------------------------------

%clean_speech = clean_speech - mean(clean_speech); %processed_speech = processed_speech - mean(processed_speech);

%processed_speech = processed_speech.*(max(abs(clean_speech))/ max(abs(processed_speech)));

overall_snr = 10* log10( sum(Speech.^2)/sum((Speech-Enhanced_speech).^2));

% ---------------------------------------------------------------------- % Global Variables % ----------------------------------------------------------------------

% sample_rate = 8000; % default sample rate % winlength = 240; % window length in samples % skiprate = 60; % window skip in samples winlength = fix(30*sample_rate/1000); %240; % window length in samples skiprate = floor(winlength/4); % window skip in samples MIN_SNR = -10; % minimum SNR in dB MAX_SNR = 35; % maximum SNR in dB

% ---------------------------------------------------------------------- % For each frame of input speech, calculate the Segmental SNR % ----------------------------------------------------------------------

num_frames = clean_length/skiprate-(winlength/skiprate); % number of frames start = 1; % starting sample window = 0.5*(1 - cos(2*pi*(1:winlength)'/(winlength+1)));

for frame_count = 1: num_frames segmental_snr = zeros(1,num_frames); % ---------------------------------------------------------- % (1) Get the Frames for the test and reference speech. % Multiply by Hanning Window. % ----------------------------------------------------------

   clean_frame = Speech(start:start+winlength-1);
   processed_frame = Enhanced_speech(start:start+winlength-1);
   clean_frame = clean_frame.*window;
   processed_frame = processed_frame.*window;

   % ----------------------------------------------------------
   % (2) Compute the Segmental SNR
   % ----------------------------------------------------------

   signal_energy = sum(clean_frame.^2);
   noise_energy  = sum((clean_frame-processed_frame).^2);
   segmental_snr(frame_count) = 10*log10(signal_energy/(noise_energy+eps)+eps);
   segmental_snr(frame_count) = max(segmental_snr(frame_count),MIN_SNR);
   segmental_snr(frame_count) = min(segmental_snr(frame_count),MAX_SNR);

   start = start + skiprate;
   segSNR= mean( segmental_snr);
end

and I receive this message: Output argument 'segmental_snr' is not assigned on some execution paths. how can I tackle this? Thanks in advance