Comparing two sequences of number but not symmetry

Hi, I'm not sure under what section to ask.

But it is like asking general math formulation. I currently create a function to assingn a sequence of number into increasing order and decreasing order.

For example when I consider N=10, for decreasing, I set the Peak to 1, and for increasing, I set the peak to N=10. However when i compare both sequence, it does not give symmetry pattern.

Hoping someone can give me a hint if the formulation for Dmaxp1(2,k) need to be changed?

Thank you in advance.

solution:

10    10    10    10     9     9     8     8     7     7 %This is when peak =1
 6     7     7     7     8     8     9     9    10    10 %This is when peak=N=10;

code;

function[AllVal]=GenPer(N)

Trend=0.05;
MaxD=10;
MinD=0;
Peak=10;

AllVal=zeros(3,N); %Output save in here
day=AllVal(1,:);
DmaxP1=AllVal(2,:);
DminP1=AllVal(3,:);
PeakD1=1:1:Peak; %number before peak day
PeakD2=Peak+1:1:N; %Number after peak day

for k=PeakD1
    day(1,k)=k;
    DmaxP1(2,k)=ceil(MaxD*(1-Trend)^(Peak-(k-1)));
    DminP1(3,k)=MinD;
    
    %Output
    AllVal(1,k)=day(1,k);
    AllVal(2,k)=DmaxP1(2,k);
    AllVal(3,k)=DminP1(3,k);
end
for k=PeakD2
    day(1,k)=k;
    DmaxP1(2,k)=ceil(MaxD*(1-Trend)^((k-1)-Peak));
    DminP1(3,k)=MinD;
    
    %Output
    AllVal(1,k)=day(1,k);
    AllVal(2,k)=DmaxP1(2,k);
    AllVal(3,k)=DminP1(3,k);
end

end

[Image Analyst]

I'm not sure what you're asking. Maybe have someone help you re-word it to explain better. Do you want to find the peak or max? Do you have the Signal Processing Toolbox so you can use its findpeaks() function?

Answer 1

[Athul Prakash]

Hey Hafizah,

Couldn't understand what you're trying to model here, so I can't comment on a different formula for DmaxP1(2, k).

However, I understand that you're confused by non-symmetric values you got for Peak=10 and Peak=1.

You can solve this issue by changing your indices in the formula as follows:

% Replace this line in the first for loop.
DmaxP1(2,k)=ceil(MaxD*(1-Trend)^(Peak-(k-1)));     % your current code.
DmaxP1(2,k)=ceil(MaxD*(1-Trend)^(Peak-(k)));       % replacement code to fix the issue.

% make a similar replacement in the second for loop also;  change (k-1) to k

The code is assuming 0-indexed vector, but matlab is 1-indexed. Hence, you are producing peaks at index=Peak+1.

The above change fixes the issue.