The input character is not valid in MATLAB statements or expressions

The following code was running. But from today I found this error.

clear all;
close all;
clc
sample_dna2 = fastaread('MT450872_covid.fasta');
sample_dna2 = struct2cell(sample_dna2);
sample_dna2 = cell2mat(sample_dna2(2));
seq2 = sample_dna2(1:29782);
[x2] = dna_binary_double(seq2);
DNAWALK2 = cumsum(x2);
dwtmode('per');
[C,S] = wavedec(x2,8,'coif4');
 A5 = appcoef(C,S,'coif4',8);

The total error message is showing as-

Error: File: appcoef.m Line: 1 Column: 4

The input character is not valid in MATLAB statements or expressions.

Error in DNAWALK (line 12)

A5 = appcoef(C,S,'coif4',8);

Please help.

[Stephen23]

Please show us the output of this command:

which appcoef -all

[SUBHAJIT KAR]

Here is the output of the command -'which appcoef -all':

C:\Program Files\MATLAB\R2016a\toolbox\wavelet\wavelet\appcoef.m

[SUBHAJIT KAR]

Any recomendation to solve the problem? I think the inbuilt function is not working.

Answer 1

[Steven Lord]

Have you opened the appcoef function in the Editor previously, even accidentally? If so, open it in the Editor again and see if you'd accidentally typed something in line 1 column 4 of the file when you had it open previously. Don't make any other changes to it, and if you do need to eliminate the extra character save the file and close its tab in the Editor as soon as possible.

[SUBHAJIT KAR]

How to open appcoef function in editor? Any particular command?

[Steven Lord]

Use the edit function.

Answer 2

[Jay Delfin]

??? Error: File: Untitled9.m Line: 1 Column: 11

The input character is not valid in MATLAB statements or expressions. how to fix this

M = input(’Matrix size:’);

A = zeros(M);

A(1,1:M-1) = 1;

A(1:M-1,M) = 2;

A(M,2:M) = 3;

A(2:M,1) = 4;

figure, imagesc(A), axis equal off

[Steven Lord]

M = input(’Matrix size:’);

Character 11 looks like a "smart quote", inserted perhaps by Microsoft Word as a replacement for a regular single quote. Replace it with a regular single quote.

M = input('Matrix size:');

[khan aijaz]

p = [0.8 –0.44 0.36 0.02];

d = [1 0.7 -0.45 -0.6];

N = 41; % Desired impulse response length

x = [1 zeros(1,N-1)];

y = filter(p, d, x);

k = 0:1:N-1;

stem(k,y)

xlabel(‘Time index n’)

ylabel(‘Amplitude’)

my error Error: File: lab6.m Line: 1 Column: 11

The input character is not valid in MATLAB statements or expressions.

please help me to find the solution?

[Steven Lord]

I'm guessing the character before the 0.44 on that first line is not a hyphen (-) but is instead a dash, inserted by Microsoft Word or Microsoft Outlook. Compare the line copied from your post (the first line below) and a copy of that line where I selected the dash and pressed the hyphen key on my keyboard (the second line below.) The second of those commands should run and the first should error.

p = [0.8  –0.44  0.36  0.02];
p = [0.8  -0.44  0.36  0.02];

[Les Beckham]

And, as in @Steven Lord's answer from 14 Jun 2021, the single quote characters in the xlabel and ylabel command lines are also not normal single quote characters.

double('‘T...n’')

ans = 1×7

8216 84 46 46 46 110 8217

double('''')

ans = 39