Unexpected MATLAB expression- can you help?

2 次查看（过去 30 天）
Margery
Margery 2015-4-8
评论： Steven Lord 2023-7-4
I'm testing out the below code but I keep on getting this error: Error: File: program1.m Line: 1 Column: 8 Unexpected MATLAB expression. How do I fix this problem?
%(Image Enhancement)
image=imread('thumb.jpg');
function [final]=fftenhance(image,f) I = 255-double(image);
[w,h] = size(I);
%out = I;
w1=floor(w/32)*32; h1=floor(h/32)*32;
inner = zeros(w1,h1);
for i=1:32:w1
for j=1:32:h1
a=i+31;
b=j+31;
F=fft2( I(i:a,j:b) ); factor=abs(F).^f;
block = abs(ifft2(F.*factor)); larv=max(block(:));
if larv==0
larv=1; end;
block= block./larv;
inner(i:a,j:b) = block; end;
end;
final=inner*255;
final=histeq(uint8(final));

请先登录，再回答此问题。

采纳的回答

Stephen23
Stephen23 2015-4-8
编辑：Stephen23 2015-4-9
The first line of your code above has a commented-out line for the first line, so there must be something that you are not showing us which is causing this error message.
Nonetheless, here are a few tips for getting your code working:
  • Do not use the variable name image, as this is the name of a very useful inbuilt function image.
  • It is an error to write both a script and a function in one file, which is what you are trying to do here. The first code line image=imread('thumb.jpg');, without a preceding function declaration, tells MATLAB that this is a script. Then you follow this with a function declaration, thus making both a script and a function in one file. It is not possible to do both in one file: either the whole file must be one script (no functions) or the file can consist only of functions.
  • Do not use i and j as variable names, as these are the names of the inbuilt imaginary unit.
  5 个评论
显示 3更早的评论
rahul hanot
rahul hanot 2016-11-2
fftehance fuction is having 2 argument one is image and wht is the 2nd arrugument f can anyone plz tellme the value of f

请先登录，再进行评论。

更多回答（1 个）

Daniel Quiteque
Daniel Quiteque 2023-7-4
Hello people!
Please, can some of you help me?
aim trying to code this script, but alwau=ys give me a wrong.
% Demonstration of BPSK tx/rx chain (waveform simulation)
clearvars ; clc; clear all
N=100000;%Number of symbols to transmit
EbN0dB = -4:2:10; % Eb/N0 range in dB for simulation
L=16;%oversampling factor,L=Tb/Ts(Tb=bit period,Ts=sampling period)
%if a carrier is used, use L = Fs/Fc, where Fs >> 2xFc
Fc=800; %carrier frequency
Fs=L*Fc;%sampling frequency
EbN0lin = 10.^(EbN0dB/10); %converting dB values to linear scale
BER = zeros(length(EbN0dB),1); %for SER values for each Eb/N0
ak = rand(N,1)>0.5; %random symbols from 0's and 1's
[s_bb,t]= bpsk_mod(ak,L); %BPSK modulation(waveform) - baseband
s = s_bb.*cos(2*pi*Fc*t/Fs); %with carrier
%Waveforms at the transmitter
subplot(2,2,1);plot(t,s_bb);%baseband wfm zoomed to first 10 bits
xlabel('t(s)');
ylabel('s_{bb}(t)-baseband');
xlim([0,10*L]);
subplot(2,2,2);plot(t,s); %transmitted wfm zoomed to first 10 bits
xlabel('t(s)'); ylabel('s(t)-with carrier');xlim([0,10*L]);
%signal constellation at transmitter
subplot(2,2,3);plot(real(s_bb),imag(s_bb),'o');
xlim([-1.5 1.5]); ylim([-1.5 1.5]);
for i=1:length(EbN0dB),
Eb=L*sum(abs(s).2)/length(s); %signal energy
N0= Eb/EbN0lin(i); %Find the noise spectral density
n = sqrt(N0/2)*randn(1,length(s));%computed noise
r = s + n;%received signal with noise
r_bb = r.*cos(2*pi*Fc*t/Fs);%recovered baseband signal
ak_cap = bpsk_demod(r_bb,L);%baseband correlation demodulator
BER(i) = sum(ak=ak_cap)/N;%Symbol Error Rate Computation
%Received signal waveform zoomed to first 10 bits
subplot(2,2,4);plot(t,r);%received signal (with noise)
xlabel('t(s)'); ylabel('r(t)');xlim([0,10*L]);
pause;%wait for keypress
end
theoreticalBER = 0.5*erfc(sqrt(EbN0lin));%Theoretical bit error rate
figure;semilogy(EbN0dB,BER,'k*'); %simulated BER
hold on;semilogy(EbN0dB,theoreticalBER,'r-');
xlabel('E_b/N_0 (dB)'); ylabel('Probability of Bit Error - P_b');
legend('Simulated', 'Theoretical');grid on;
title(['Probability of Bit Error for BPSK modulation']);
  1 个评论
Steven Lord
Steven Lord 2023-7-4
Since this doesn't seem related to the original question, you should ask this as a separate question using the Ask link near the top of this page.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 MATLAB 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by