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I want the Matlab to recognize colors and analyse the object if it yellow otherwise it would ignore it.
I know how to analyze the objects but I don't know how to eliminate the other non-yellow ones
The most simple approach that I can come up with is this quick and dirty program:
i = imread('school_zone.jpg');
r = i(:,:,1);
g = i(:,:,2);
b = i(:,:,3);
threshold = 100;
isyellow = r > threshold & g > threshold & b < threshold;
(b < threshold to prevent the white to be confused with yellow)
imshow(isyellow);
Related
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syms k
S1 = symsum(1/((2*k)+1)^2,k,0,1000)
The result is this
59039372973827482202940226722672826425297321906316082356858983822169051832268260251807527611479190413293513875429587706186073872918905490907386679472102966658686481651660967093301512141946288248492833396616338323741632085379508599235923841007033467883638349122388806376761808189104503262045883240287482992169819848342303098664924237976221795758421152603069387903705445513260596627332283139648508194960733619500093010571517561429904500013876585156927070119332440687162376758374919870699278800835146651318465663183182583101377584105366558079836223068786457324044080570317649838092783113721959819118571747662368360095513856052974454509201490370810246175872510881504730747209788019551000695511879992198550955686739483474761130248789609061549535677663474218135370195381615899214931316241080337028498241295985409686314819267606796712968280842464845294917738460317179001491697993067157425958639996885239616893392960282441289069600101430806922004624472226999315951355963789249300352610312601262349650287009275097201871774652260892220551489305368617001974326978428202443548923140478853569492070442010110016068635424791389124439271253578545895132216218268847919848655110002938693346760862649668457282775860633067627110099340660770861888592018701206483696615682617062811616008107086256694453990688805738127607846586853460003073465075155412119309273843527076321601670400373937698518621100907936577387919537592519265365346619712200304996044229704602647674114176291753575322917531444831938509001759491229575945273985556769609288625450013634760596805884195325794441020339210402987018058377081579351119704065092777310976461961832919116412535470810011337916688085616171422473409544885864650134157327448050685723673514545806331081542320899927
It is a number in this form a/b
Why is this happening??
Do you know how to do this in octave too?
k = (0:1000);
k_sum = sum(1./((2*k)+1).^2);
disp(k_sum)
It's interesting that you jumped straight to using syms when the basic matlab functions work perfectly well for this problem. Why is that?
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How to represent this equation to matlab code
Like so:
function y = sgn(x)
if x == 0
y = 0;
else
y = x / abs(x);
end
end
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I want to perform integration on a vector L but I don't know exactly what to use. I want to obtain a (the integral) as a vector that is the same size as NT.
clc;clear;
syms x
NT=input('NT=');
L=zeros(NT,1);
for i=1:NT
disp('Longeur de travée')
L(i)=input('L = ');
L(i)=L(i);
fa(i)=L(i).*x^2;
a(i)=int(fa)
end
An easy way would be to use trapz. If you have X and Y such that Y(i) = f(X(i)) (so Y contains the values of some function at the location X) then you simply do
I = trapz(X, Y)
In your case, you can do
I = trapz(L, fa)
I guess, looking at your code.
Note that you could use more advanced techniques, that will, in principle, give you a better result (because they are higher-order). This is just one method, but an easy one.
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Please help me out with this code:
for i = 1:n
u(t - a_i - td_i);
end
where:
u: step function
t: time vector with n elements
a_i, tau_i, and td_i: variables that change inside for loop
I guess I need to use zeros and ones, but how can I do this correctly?
Simple function to sum the value inside the loop:
func = #(t) sum(t > a + td)
func(t) will be the sum of the foor loop
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I have 2 data set point cloud and I want to crop a part of them together.
Because of volume of them is too too large I couldn't crop them with below codes.
Can you help me to how can I crop them?
Used codes are:
selectedl=[];%% last pulse
for i=1:size(indexl)
selectl=lr(indexl(i),:);
selectedl=[selectedl;selectl];
end
selectedf=[];%% first pulse
for i=1:size(indexf)
selectf=fr(indexf(i),:);
selectedf=[selectedf;selectf];
end
Thank U all.
It is a bit difficult to understand what you want to do, as lr, fr, indexl and indexf are missing.
But assuming something like
lr = rand(5,3) ;
indexl = [2 5] ;
I would advise to allocate selectedl above the loop
selectedl = NaN(length(indexl),size(lr,2)) ;
for i = 1:length(indexl)
selectedl(i,:) = lr(indexl(i),:) ;
end
This might not be needed for this example, but if the data size becomes larger this will speed up the loop.