I want to compute the following sum :
I have tried using the following code :
I = imread('C:\Users\Billal\Desktop\image.png');
[x,y,z]=size(I);
x=(1:x) ;
y=(1:y) ;
z=(1:z) ;
Fx=ones(size(x));
Fy=ones(size(y));
Fz=ones(size(z));
X=x*Fy';
Y=Fx*y';
Z=z*Fz';
f=I(X,Y,Z);
sum1 = sum(f(:));
[x1,y1,z1]=size(I);
total = sum1/(x1*y1*z1);
But the result is 0 . I could not figure out where is the problem ? I am following this tutorial .
https://www.mathworks.com/matlabcentral/newsreader/view_thread/126366
Please help me to solve this question .
You can do this in a single step:
result=1/prod(size(I))* sum(I(:));
In the end, the equation just adds up values of the whole image.
The question you link to needs to sum over values of x and y. You don't, you just need to sum over indexes, thus there is no need of all those Fx,Fy things
Related
I'm looking forward to assign a specific count of persons to a specific shift. For example I got six persons and three different shifts. Now I have to assign exact two persons to every shift. I tried something like this but..
NOTE: this won't work, so please edit as fast as possible to misslead people, I even removed the "." after it so nobody is copying it:
person(a)
person(b)
person(c)
person(d)
person(e)
person(f)
shift("mor")
shift("aft")
shift("nig")
shiftCount(2).
{ assign(P,S) : shift(S)} = 1 :- person(P).
% DO NOT COPY THIS! SEE RIGHT ANSWER DOWN BELOW
:- #count{P : assign(P,"mor")} = K, shiftCount(K).
:- #count{P : assign(P,"aft")} = K, shiftCount(K).
:- #count{P : assign(P,"nig")} = K, shiftCount(K).
#show assign/2.
Is this possible to count the number of assigned shifts, so I can assign exactly as many people as a given number?
The output of the code above (when the "." are inserted) is:
clingo version 5.5.0
Reading from stdin
Solving...
Answer: 1
assign(a,"nig") assign(b,"aft") assign(c,"mor") assign(d,"mor")
assign(e,"mor") assign(f,"mor")
SATISFIABLE
Models : 1+
Calls : 1
Time : 0.021s (Solving: 0.00s 1st Model: 0.00s Unsat: 0.00s)
CPU Time : 0.000s
Here you can defently see, that the morning ("mor") shift is used more than two times, as difined in the shiftCount. What do I need to change to get the wanted result?
Replace your 3 lines constraints with
{assign(P,S): person(P)} == K :- shift(S), shiftCount(K).
or alternatively if you want to use the constraint writing:
:- {assign(P,S): person(P)} != K, shift(S), shiftCount(K).
First line states: For a given shiftCount K and for every shift S: the number of assignments over all people P for this shift S is K.
The constraint reads: it can not be the case for a shiftCount K and a shift S that the number of assignments over all people P to the shift S is not K.
Please do not alter your question / sample code dramatically since this may leads to the case that this answer won't work anymore.
I have a problem I hope you can help me with.
I have imported a large dataset (200000 x 5 cell) in Matlab that has the following structure:
'Year' 'Country' 'X' 'Y' 'Value'
Columns 1 and 5 contain numeric values, while columns 2 to 4 contain strings.
I would like to arrange all this information into a variable that would have the following structure:
NewVariable{Country_1 : Country_n , Year_1 : Year_n}(Y_1 : Y_n , X_1 : X_n)
All I can think of is to loop through the whole dataset to find matches between the names of the Country, Year, X and Y variables combining the if and strcmp functions, but this seems to be the most ineffective way of achieving what I am trying to do.
Can anyone help me out?
Thanks in advance.
As mentioned in the comments you can use categorical array:
% some arbitrary data:
country = repmat('ca',10,1);
country = [country; repmat('cb',10,1)];
country = [country; repmat('cc',10,1)];
T = table(repmat((2001:2005)',6,1),cellstr(country),...
cellstr(repmat(['x1'; 'x2'; 'x3'],10,1)),...
cellstr(repmat(['y1'; 'y2'; 'y3'],10,1)),...
randperm(30)','VariableNames',{'Year','Country','X','Y','Value'});
% convert all non-number data to categorical arrays:
T.Country = categorical(T.Country);
T.X = categorical(T.X);
T.Y = categorical(T.Y);
% here is an example for using categorical array:
newVar = T(T.Country=='cb' & T.Year==2004,:);
The table class is made for such things, and very convenient. Just expand the logic statement in the last line T.Country=='cb' & T.Year==2004 to match your needs.
Tell me if this helps ;)
I'm making a GUI in matlab to calculate ideal shifting points for a racecar.
For this I need to compare 2 single column matrixes.
Fwheel1 =
1.0e+003 *
4.5433
4.6372
4.6770
4.6892
4.7235
4.8064
4.9451
5.0838
5.2300
5.3401
5.4864
5.5454
5.5046
5.4758
5.5028
5.5782
5.6183
5.6663
5.7380
5.8174
5.8940
5.9553
6.0364
6.1075
6.0904
5.9285
5.7654
5.5762
5.3498
5.1766
5.0548
4.8236
4.6538
Fwheel2 =
1.0e+003 *
3.5174
3.5901
3.6209
3.6304
3.6569
3.7211
3.8285
3.9358
4.0490
4.1343
4.2475
4.2932
4.2617
4.2393
4.2602
4.3186
4.3496
4.3868
4.4423
4.5038
4.5631
4.6105
4.6734
4.7284
4.7151
4.5898
4.4635
4.3170
4.1418
4.0077
3.9134
3.7344
3.6029
These are the 2 matrixes. Now what I want is to compare Fwheel1 with Fwheel2. I want to know at which position in the matrix Fwheel2 > Fwheel1.
So output needs to be for example 23.
I hope somebody can help me.
Kind regards
You can do this easily with find.
idx= find( Fwheel2 > Fwheel1);
If you just want the first one, or the first n, you can just
idx= find( Fwheel2 > Fwheel1,n);
for another method,
c=0;
for i=1:33
if Fwheel2(i)>Fwheel1(i)
c=c+1;
b[c]=i
end
end
in the b vector you have your answer
As simple as in title. I have nx1 sized vector p. I'm interested in the maximum value of r = p/foo - floor(p/foo), with foo being a scalar, so I just call:
max_value = max(p/foo-floor(p/foo))
How can I get which value of p gave out max_value?
I thought about calling:
[max_value, max_index] = max(p/foo-floor(p/foo))
but soon I realised that max_index is pretty useless. I'm sorry asking this, real beginner here.
Having dropped the issue to pieces, I realized there's no unique corrispondence between values p and values in my related vector p/foo-floor(p/foo), so there's a logical issue rather than a language one.
However, given my input data, I know that the solution is unique. How can I fix this?
I ended up doing:
result = p(p/foo-floor(p/foo) == max(p/foo-floor(p/foo)))
Looks terrible, so if you know any other way...
Once you have the index, use it:
result = p(max_index)
You can create a new vector with your lets say "transformed" values:
p2 = (p/foo-floor(p/foo))
and then just use find to find the max values on p2:
max_index = find(p2 == max(p2))
that will return the index or indices of p2 with the max value of that operation, and finally just lookup the original value in p
p(max_index)
in 1 line, this is:
p(find((p/foo-floor(p/foo) == max((p/foo-floor(p/foo))))))
which is basically the same thing you did in the end :)
This is quite a simple issue, but I've been struggling with it. sortedd and sortedfinal_d are 8 x 1000 Matrices and I am using the loop below to check if any of the elements in sortedfinal_d lies between two consecutive elements of sortedd, in terms of magnitude. I'm doing this along each row. overall_p is a 8 x 1000 Matrix as well, but at the end of this process I end up having final_p as a Matrix of Zeros. I don't know why this is.
for k=2:1000
for s=1:1000
for j=1:8
if sortedd(j,k) > sortedfinal_d(j,s) && sortedfinal_d(j,s) > sortedd(j,k-1)
final_p(j,s) = overall_p(j,k);
end
end
end
end
EDIT: Added data for the inputs as shown below:
sortedd (first four columns) =
0.219977361620113 0.219996752039812 0.220344444223787 0.220593274018691
0.272807483153955 0.273682693068593 0.273846498221277 0.274060049642900
0.327201460264565 0.327375792227635 0.327572790857546 0.327856448530021
0.380389118311424 0.380845274148177 0.380893687870765 0.381015090963159
0.434832574575088 0.434860658844550 0.435021604722982 0.435119929919457
0.487119089589798 0.488128501559782 0.488207451439073 0.488430455768512
0.540652551559395 0.541303305046034 0.542195194863130 0.542234381085921
0.595254195563241 0.595296064375604 0.595376090156252 0.595377962767971
sortedfinal_d =
0.182086792394190 0.182406508309366 0.182406508309366 0.182808976400818
0.233058295607543 0.233058295607543 0.233158455616954 0.233158455616954
0.286243848617693 0.286357973626582 0.286918095670684 0.287393171241241
0.336938335090164 0.336938335090164 0.337094505106945 0.337669618738100
0.390287818652551 0.390567879874952 0.390567879874952 0.390670502700602
0.446995120903824 0.447270251510681 0.447452123072880 0.447597175111267
0.501060785098551 0.501060785098551 0.501060785098551 0.501060785098551
0.551311219045087 0.551463923687602 0.551463923687602 0.551653815175502
Thanks a lot
Do you have to use loops to accomplish this?
matching_d = sortedfinal_d(:,1:end-1) < sortedd(:,2:end) ...
& sortedd(:,2:end) < sortedfinal_d(:,2:end);
final_p(matching_d) = overall_p(matching_d);
If you can show us a small sample input (say, 1x5 versions of sortedd and sortedfinal_d) and output (the corresponding matching_d) it would be easier for us to help troubleshoot.
If i set your matrices to random numbers, final_p does return some numbers.
So your code works as is. Post your dataset or at least describe the dataset in some detail, this will make it much easier to diagnose the problem.
I have reduced 1000 down to 10 and re-ordered the iteration variables to i, j, k to make it easier to follow:
sortedd = rand(8, 10);
sortedfinal_d = rand(8, 10);
overall_p = rand(8, 10);
for i=2:10
for j=1:10
for k=1:8
if sortedd(k,i) > sortedfinal_d(k,j) && sortedfinal_d(k,j) > sortedd(k,i-1)
final_p(k,j) = overall_p(k,i);
end
end
end
end
final_p