这是一个CRC校验码的matlab实现的程序 我运行不出来 不知道哪里有错误 麻烦懂的人的能够帮我改正一下！

Question

%main program
clear all;
input=[1 1 0 0]
CRC_Number=[3 8 12 16];
for crc_index = 1:size(CRC_Number,2)
crc_no = CRC_Number(crc_index)
output = crc_add(input, crc_no)
[output_after_check, indicate] =crc_check(output,crc_no)
end
function [ output, indicate] = crc_check( input, crc_no )
% the function is proposed for deleting crc bits from the input sequence
n = size(input,2);
generator = zeros(1,crc_no+1);
output = zeros(1,n-crc_no);
switch crc_no
case 3
generator = [1 0 1 1];
case 8
generator = [1 1 0 0 1 1 0 1 1]; %D^8+D^7+D^4+D^3+D+1
case 12
generator = [1 1 0 0 0 0 0 0 0 1 1 1 1]; %D^12+D^11+D^3+D^2+D+1
case 16
generator = [1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1]; %D^16+D^12+D^5+1
case 24
generator = [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 1]; %D^24+D^23+d^6+D^5+D+1
otherwise
fprintf('\nPlease the number of crc bits should be 8 12 16 24\n');
end
output = input(1:n-crc_no);
for ii = 1:n-crc_no
if(input(1) == 1)
input(1:crc_no+1) = mod((input(1:crc_no+1)+generator),2);
end
input = [input(2:end) input(1)];
end
if sum(input) == 0
indicate = 0;
else
indicate = 1;
end
function [ output ] = crc_add( input, crc_no )
% the function is proposed for adding crc bits to the input sequence
k = size(input,2);
generator = zeros(1,crc_no+1);
output = zeros(1,k+crc_no);
switch crc_no
case 3
generator = [1 0 1 1];
case 8
generator = [1 1 0 0 1 1 0 1 1]; %D^8+D^7+D^4+D^3+D+1
case 12
generator = [1 1 0 0 0 0 0 0 0 1 1 1 1]; %D^12+D^11+D^3+D^2+D+1
case 16
generator = [1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1]; %D^16+D^12+D^5+1
case 24
generator = [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 1]; %D^24+D^23+d^6+D^5+D+1
otherwise
fprintf('\nPlease the number of crc bits should be 8 12 16 24\n');
end
output(1:k)=input;
for ii = 1:k
if(output(1) == 1)
output(1:crc_no+1) = mod((output(1:crc_no+1)+generator),2);
end
output = [output(2:end) output(1)];
end
output = [input output(1:crc_no)];

Answer 1

1 新建m文件，把函数function [ output, indicate] = crc_check( input, crc_no )贴进去保存；
2 新建m文件，把函数function [ output ] = crc_add( input, crc_no )贴进去保存；
3 在command window里输入
clear all;
input=[1 1 0 0]
CRC_Number=[3 8 12 16];
for crc_index = 1:size(CRC_Number,2)
crc_no = CRC_Number(crc_index)
output = crc_add(input, crc_no)
[output_after_check, indicate] =crc_check(output,crc_no)
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
rc_check和crc_add相当于函数，你要调用这2个函数，所以应先将函数保存，再进行调用。