clc;clear; %% 定义未知量 syms = b G_a G_bc x_a x_bc a c; %定义已知量 R = 0.3; k = 500; G = 50; F = 50; % F_a = 30; % F_bc = 20; %求解角度b e = [tan(b) == 3/4]; s = solve(e); b = b*180/pi; %求解 eqns = [(sqrt((x_bc)^2-(3/4)*R^2))/x==F_bc; k*x_a==F_a;cos(b+c)*sqrt((9/64)*R^2+(1/4)*R^2)==a; G_a*a==G_bc*((3/2)*R*cos(c)-a); cos(a)*F_a==G_a; cos(b)*F_bc==G_bc; G_a+G_bc==G+F]; vars = [G_a,G_bc,x_a,x_bc,a,c]; sol = solve(eqns,vars); %将a,c转化为弧度制 a = rad2deg(sol.a); c = rad2deg(sol.c);

这段代码是一个MATLAB程序，用于求解一个力学问题的未知量。在这个问题中，已知一些量，如R、k、G、F、F_a和F_bc等，需要求解b、G_a、G_bc、x_a、x_bc、a和c等未知量。代码中使用了MATLAB的符号计算工具箱，定义了未知量和已知量，并使用solve函数解方程组得到未知量的值。这个问题可能涉及到力学、静力学、动力学等知识。

相关问题

clc clear all %% img_in = imread('ILSVRC2017_test_00000237.jpg'); m = size(img_in,1); n = size(img_in,2); img_lab = rgb2lab(img_in); img_L_mean = mean(mean(img_lab(:,:,1))); img_a_mean = mean(mean(img_lab(:,:,2))); img_b_mean = mean(mean(img_lab(:,:,3))); %% %高斯滤波 img_R = img_in(:,:,1); img_G = img_in(:,:,2); img_B = img_in(:,:,3); w = fspecial('gaussian',[7 7]); img_R_blur = imfilter(img_R,w); img_G_blur = imfilter(img_G,w); img_B_blur = imfilter(img_B,w); img_blur = cat(3,img_R_blur,img_G_blur,img_B_blur); figure('name','滤波') imshow(img_blur) img_lab_blur = rgb2lab(img_blur); %% %计算显著图 Sd = zeros(m,n); for i = 1:m for j = 1:n Sd(i,j) = sqrt((img_L_mean - img_lab_blur(i,j,1))^2 + (img_a_mean - img_lab_blur(i,j,2))^2 + (img_b_mean - img_lab_blur(i,j,3))^2); end end %归一化 Sd_normalized = figure_normalize(Sd); imwrite(Sd_normalized,'FT_saliency.jpg') figure imshow(Sd_normalized) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function Out_image = figure_normalize(In_image) % 归一化至0-1 o_max_image = max(max(In_image)); o_min_image = min(min(In_image)); Out_image = double(In_image - o_min_image)/double(o_max_image - o_min_image); end改进该代码使其能在matlab上运行

clc;
clear all;

img_in = imread('ILSVRC2017_test_00000237.jpg');
m = size(img_in,1);
n = size(img_in,2);

img_lab = rgb2lab(img_in);
img_L_mean = mean(mean(img_lab(:,:,1)));
img_a_mean = mean(mean(img_lab(:,:,2)));
img_b_mean = mean(mean(img_lab(:,:,3)));

%高斯滤波
img_R = img_in(:,:,1);
img_G = img_in(:,:,2);
img_B = img_in(:,:,3);
w = fspecial('gaussian',[7 7]);
img_R_blur = imfilter(img_R,w);
img_G_blur = imfilter(img_G,w);
img_B_blur = imfilter(img_B,w);

img_blur = cat(3,img_R_blur,img_G_blur,img_B_blur);

figure('Name','滤波');
imshow(img_blur);

img_lab_blur = rgb2lab(img_blur);

%计算显著图
Sd = zeros(m,n);
for i = 1:m
for j = 1:n
Sd(i,j) = sqrt((img_L_mean - img_lab_blur(i,j,1))^2 + (img_a_mean - img_lab_blur(i,j,2))^2 + (img_b_mean - img_lab_blur(i,j,3))^2);
end
end

%归一化
Sd_normalized = figure_normalize(Sd);
imwrite(Sd_normalized,'FT_saliency.jpg');
figure;
imshow(Sd_normalized);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function Out_image = figure_normalize(In_image)
o_max_image = max(max(In_image));
o_min_image = min(min(In_image));
Out_image = double(In_image - o_min_image)/double(o_max_image - o_min_image);
end

clear all; close all; clc;tic 5%8866% Settings $8868% its_option =2; 966 0:??????，1:??????，2：?????？ hoise_option=1; 8% 0:??????，1:?????? =4;NT=2; SNRdBs=[0:2:20];sq05=sqrt(0.5); obe_target =500; BER_target =1e-3; taw_bit_len= 2592-6; nterleaving_num = 72; deinterleaving_num = 72; _frame = 1e8; or i_SNR=1:length(SNRdBs) sig_power=NI;SNRdB=SNRdBs(i_SNR); sigma2=sig_power*10°(-SNRdB/10)*noise_option;sigmal=sqrt(sigma2/2); nobe = 0; Viterbi_init for i_frame=1:1:N_frame I %%88688868896%% ??????866988689686836% switch (bits_option) case (0】, bits=zeros(1,raw_bit_len); case (11, bits=ones(1,raw_bit_len); casef2), bits=randint(1,raw_bit_len); case (2), bits=randi(1,1,raw_bit_len)-1; end 686%6% ?????88%6% encoding_bits= convolution_encoder(bits); 6%%8%% ????? 8686% interleaved=[]; for i=l:interleaving_mum interleaved=[interleavedencoding_bits([i:interleaving_mum:end])];for tx_time-l:648 tx_bits=interleaved(1:8); interleaved(1:8)=[J; ??7 QAM16_symbol=QAM16_mod(tx_bits, 2); ?????69686666366685669 x(1,1) =QAM16_symbol(1);x(2,h)=QAM16_symbol(2); 90969696%????????????? 636585863666666 if rem(tx_time-1,81)==0 H = sq05*(randn(2,2)+j*randn(2,2)); end y =H*x; 66986896%88868% ????? 6688688%%88%% noise = sqrt(sigma2/2)*(randn(2,1)+j*randn(2,1)); if noise_option==1, y = y + noise;end %8%8%88%%8%8% ??????668888688888%% W=inv(H'*H+sigma2*diag (ones(1,2)))*H'; K_tilde =W*y; %%%%88%%8%8% ??????668888%58888%% x_hat = QAM16_slicer(X_tilde, 2); temp_bit=[temp_bit QAM16_denapper(X_hat, 2)]; end %%%8%%%%?????88%8886% deinterleaved=[]; for i=1:deinterleaving_rum deinterleaved=[deinterleaved temp_bit([i:deinterleaving_mum:end])];end %%%86%%%?22220%%%866% received_bit=Viterbi_decode(deinterleaved) 600%%22222 5%0%% for EC_dummy=1:1:raw_bit_len, A bit(BC dumnv) nahesnobe+1:endif nobe>=nobe_target, break; end end if (nobe>=nobe_target) break; end end %8%888888%%%%save BER data & Display 8%88%8888%88%BER(i_SNR)=nobe/((i_frame-1)*raw_bit_len+EC_dummy);fprintf(’t%dt\t%1.4f\n', SNRdB,BER(i_SNR)); if BER(i_SMR)<BER_target, break; end end详细注释这段matlab代码

这段MATLAB代码实现了一个通信系统的模拟。首先设置了一些参数，包括使用的编码方式、噪声选项、帧数、信噪比等。然后进入一个主循环，循环中对于每一帧数据，进行编码、交织、调制、信道传输、解调、反交织、译码等操作，并计算误比特率（BER）。如果达到预设的误比特率目标或帧数目标，则退出循环。最后输出信噪比和误比特率，并保存数据。注释中对于每个操作都有详细的说明。