How can I avoid looping here?

Hi all,

I want to avoid using for loop in part of my code to make it more efficient. Can anyone give me idea regarding this?

STD_w=0.05;
STD_gama=5;
mean_w=linspace(15,40,10);
sigma_w=ones(1,length(mean_w))*STD_w;
mean_gama=linspace(115,85,10);
sigma_gama=ones(1,length(mean_w))*STD_gama;
mean_k=zeros(1,length(mean_w));
mean_L=zeros(1,length(mean_w));
for j=1:length(mean_w)
    mean_k(j)=(0.0833/2)*(0.01*10^(0.022*mean_gama(j))+0.085*10^(0.008*mean_gama(j))*mean_w(j)+(0.9*log10(mean_w(j))-0.2)*10^(0.01*mean_gama(j)));
    mean_L(j)=144*0.01*mean_w(j)*mean_gama(j);
end

Answer 1

[Torsten]

STD_w=0.05;
STD_gama=5;
mean_w=linspace(15,40,10);
sigma_w=ones(1,length(mean_w))*STD_w;
mean_gama=linspace(115,85,10);
sigma_gama=ones(1,length(mean_w))*STD_gama;
mean_k=(0.0833/2)*(0.01*10.^(0.022*mean_gama)+0.085*10.^(0.008*mean_gama).*mean_w+(0.9*log10(mean_w)-0.2).*10.^(0.01*mean_gama))

mean_k = 1×10

1.0879 1.1155 1.1314 1.1384 1.1386 1.1332 1.1234 1.1100 1.0936 1.0748

mean_L=144*0.01*mean_w.*mean_gama

mean_L = 1×10

1.0e+03 * 2.4840 2.8587 3.2067 3.5280 3.8227 4.0907 4.3320 4.5467 4.7347 4.8960

Answer 2

[Alberto Cuadra Lara]

Hello Behrooz,

By using elementwise operators {.* .^ ./}.

Best,

Alberto

% Definitions
STD_w=0.05;
STD_gama=5;
mean_w=linspace(15,40,10);
sigma_w=ones(1,length(mean_w))*STD_w;
mean_gama=linspace(115,85,10);
sigma_gama=ones(1,length(mean_w))*STD_gama;
mean_k=zeros(1,length(mean_w));
mean_L=zeros(1,length(mean_w));

% With loop
for j=1:length(mean_w)
    mean_k(j)=(0.0833/2)*(0.01*10^(0.022*mean_gama(j))+0.085*10^(0.008*mean_gama(j))*mean_w(j)+(0.9*log10(mean_w(j))-0.2)*10^(0.01*mean_gama(j)));
    mean_L(j)=144*0.01*mean_w(j)*mean_gama(j);
end

% Without loop
mean_k_2 = (0.0833/2)*(0.01*10.^(0.022*mean_gama) + 0.085*10.^(0.008*mean_gama) .* mean_w + (0.9*log10(mean_w)-0.2) .* 10.^(0.01*mean_gama));
mean_L_2 = 144 * 0.01 * mean_w .* mean_gama;

% Checks
FLAG_CHECKS = isequal(mean_k, mean_k_2) && isequal(mean_L, mean_L_2)

FLAG_CHECKS = logical
   1